Blood test alt normal range. Understanding ALT Levels: Normal Ranges, Causes of Elevation, and Health Implications

09.07.197815.11.2021 by alexxlab

What are the normal ranges for ALT levels in blood tests. How do factors like gender and BMI affect ALT levels. What causes elevated ALT levels and what are the health implications. How can ALT levels be used to diagnose liver conditions.

Содержание

What is ALT and Why is it Important?

Alanine aminotransferase (ALT) is an enzyme found primarily in liver cells. When liver cells are damaged, ALT is released into the bloodstream. Measuring ALT levels through a blood test is a crucial way to assess liver health and function.

ALT blood tests are important for several reasons:

Detecting liver damage or disease
Monitoring progression of liver conditions
Screening for liver problems in asymptomatic patients
Evaluating effectiveness of treatments for liver disorders

Elevated ALT levels can indicate various liver issues, from mild inflammation to severe diseases like hepatitis or cirrhosis. Understanding normal ALT ranges and what causes elevations is key for proper interpretation of test results.

Normal ALT Ranges: What the Research Shows

Historically, the upper limit of normal (ULN) for ALT was set around 40 U/L. However, recent research suggests these ranges may need revision. A study of Iranian blood donors provides insights into more accurate normal ranges:

Non-overweight women (BMI < 25): ULN of 34 U/L
Non-overweight men (BMI < 25): ULN of 40 U/L

These findings highlight the importance of considering factors like gender and BMI when interpreting ALT results. The study also found that ALT levels were independently associated with BMI and male gender, but not with age.

Why are gender-specific ranges important?

Men typically have higher ALT levels than women, likely due to differences in body composition and hormones. Using gender-specific ranges can improve the accuracy of liver health assessments and avoid misdiagnosis.

Factors Influencing ALT Levels

Several factors can impact ALT levels, even in healthy individuals. Understanding these can help interpret test results more accurately:

Gender: Men generally have higher ALT levels than women
Body Mass Index (BMI): Higher BMI is associated with elevated ALT
Medications: Some drugs can affect liver enzyme levels
Alcohol consumption: Regular or excessive drinking can raise ALT
Exercise: Intense workouts may temporarily increase ALT
Diet: Certain foods and supplements can influence ALT levels

Healthcare providers should consider these factors when interpreting ALT results to avoid misdiagnosis or unnecessary concern.

Causes of Elevated ALT Levels

While slight elevations in ALT can occur in healthy individuals, significant increases often indicate liver problems. Common causes of elevated ALT include:

Viral hepatitis (hepatitis A, B, C)
Alcoholic liver disease
Non-alcoholic fatty liver disease (NAFLD)
Drug-induced liver injury
Autoimmune hepatitis
Liver cancer
Cirrhosis

In some cases, elevated ALT may be due to non-liver related issues, such as muscle damage or certain medications. This underscores the importance of comprehensive evaluation when interpreting ALT results.

How high do ALT levels need to be to indicate a problem?

ALT levels 2-3 times the upper limit of normal are generally considered mildly elevated. Levels exceeding 10 times the ULN often indicate significant liver damage or acute hepatitis. However, interpretation should always consider individual factors and be done by a healthcare professional.

ALT and Liver Disease Diagnosis

ALT testing plays a crucial role in diagnosing and monitoring liver diseases. Here’s how ALT levels can help identify specific conditions:

Acute hepatitis: Very high ALT levels (often >1000 U/L)
Chronic hepatitis: Persistently elevated ALT, usually 2-10 times ULN
NAFLD: Mild to moderate ALT elevation, often associated with obesity and metabolic syndrome
Alcoholic liver disease: ALT elevation, typically with AST:ALT ratio >2:1

While ALT is a valuable diagnostic tool, it’s important to note that normal ALT levels don’t always rule out liver disease. Some conditions, like advanced cirrhosis, may present with normal or only slightly elevated ALT.

What other tests are used alongside ALT?

ALT is often part of a liver function panel that includes:

Aspartate aminotransferase (AST)
Alkaline phosphatase (ALP)
Gamma-glutamyl transferase (GGT)
Bilirubin
Albumin

These tests, combined with clinical evaluation and imaging studies, provide a comprehensive picture of liver health.

Monitoring ALT Levels in Chronic Liver Conditions

For patients with chronic liver diseases, regular ALT monitoring is crucial. It helps assess disease progression and treatment efficacy. Here’s how ALT monitoring is used in different conditions:

Chronic hepatitis B and C: ALT levels guide antiviral treatment decisions
NAFLD: ALT helps track the effectiveness of lifestyle changes and medications
Autoimmune hepatitis: ALT is used to monitor response to immunosuppressive therapy

In these cases, the goal is often to normalize ALT levels, which can indicate reduced liver inflammation and damage.

How often should ALT be monitored in chronic liver diseases?

The frequency of ALT monitoring depends on the specific condition and treatment plan. Generally, patients may have ALT checked every 3-6 months, but this can vary. Some situations may require more frequent testing, especially when starting new treatments or during disease flares.

Lifestyle Factors and ALT Levels

Lifestyle choices can significantly impact ALT levels. Understanding these connections can help individuals maintain liver health:

Diet: A balanced, nutrient-rich diet supports liver function
Exercise: Regular physical activity can help reduce ALT levels, especially in NAFLD
Weight management: Maintaining a healthy BMI is crucial for liver health
Alcohol consumption: Limiting or avoiding alcohol can prevent ALT elevations
Medication use: Be aware of potential drug interactions and liver effects

Making positive lifestyle changes can often lead to improvements in ALT levels, particularly in conditions like NAFLD.

Can dietary supplements help lower ALT levels?

Some studies suggest certain supplements, like milk thistle or vitamin E, may help reduce ALT levels in specific conditions. However, it’s crucial to consult a healthcare provider before starting any supplement regimen, as some supplements can potentially harm the liver.

Future Directions in ALT Research and Clinical Practice

As our understanding of liver function and ALT dynamics evolves, several areas of research and clinical practice are emerging:

Refining ALT reference ranges: Developing more precise, population-specific normal ranges
ALT variability: Studying factors that cause ALT fluctuations in healthy individuals
Non-invasive fibrosis assessment: Combining ALT with other markers to evaluate liver fibrosis without biopsy
Personalized medicine: Using genetic factors to interpret ALT levels more accurately
ALT in metabolic health: Exploring the relationship between ALT and metabolic disorders

These advancements could lead to more accurate liver disease diagnosis and monitoring, improving patient outcomes.

How might AI and machine learning impact ALT interpretation?

Artificial intelligence and machine learning algorithms could potentially analyze complex patterns in ALT levels and other health data to predict liver disease risk or progression more accurately. This could lead to earlier interventions and more personalized treatment strategies.

In conclusion, understanding ALT levels and their implications is crucial for assessing and maintaining liver health. As research continues to refine our knowledge of normal ranges and influencing factors, ALT testing remains a cornerstone of liver function evaluation. By considering individual factors, lifestyle choices, and emerging research, healthcare providers can use ALT levels to guide diagnosis, treatment, and long-term health management strategies effectively.

Healthy ranges of serum alanine aminotransferase levels in Iranian blood donors

World J Gastroenterol. 2003 Oct 15; 9(10): 2322–2324.

Mehdi Mohamadnejad, Akram Pourshams, Reza Malekzadeh, Ashraf Mohamadkhani, Ali Ali Asgari, Seyed Meysam Alimohamadi, Hadi Razjooyan, Mansooreh Mamar-Abadi, Digestive Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran

Afsaneh Rajabiani, Department of Pathology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

Author contributions: All authors contributed equally to the work.

Correspondence to: Reza Malekzadeh, Digestive Disease Research Center, Tehran University of Medical Sciences, Shariati Hospital, North Kargar Avenue Tehran 14114, Iran. ri.ca.sma@kelam

Telephone: +98-21-8012992 Fax: +98-21-2253635

Received 2003 May 13; Revised 2003 Jul 13; Accepted 2003 Jul 20.

Abstract

AIM: The healthy ranges for serum alanine aminotransferase (ALT) levels are less well studied. The aim of this study was to define the upper limit of normal (ULN) for serum ALT levels, and to assess factors associated with serum ALT activity in apparently healthy blood donors.

METHODS: A total of 1939 blood donors were included. ALT measurements were performed for all cases using the same laboratory method. Healthy ranges for ALT levels were computed from the population at the lowest risk for liver disease. Univariate and multivariate analyses were performed to evaluate associations between clinical factors and ALT levels.

RESULTS: Serum ALT activity was independently associated with body mass index (BMI) and male gender, but not associated with age. Association of ALT with BMI was more prominent in males than in females. Upper limit of normal for non-overweight women (BMI of less than 25) was 34 U/L, and for non-overweight men was 40 U/L.

CONCLUSION: Serum ALT is strongly associated with sex and BMI. The normal range of ALT should be defined for male and female separately.

INTRODUCTION

Elevation of aminotransferase level is an important and common finding in different types of parenchymal liver disease. Measurement of serum ALT is one of the most important tests for detection of patients with viral hepatitis or non-alcoholic steatohepatitis (NASH), and the exact definition of upper normal levels of serum ALT activity is an initial and critical step in different screening and follow up studies for chronic liver diseases. Current upper limits of normal for ALT level are set on average, at 40 U/L. This normal range was set in the 1950s and has changed a little since then[1]. Several studies have recently questioned whether previously established values to define normal ALT range are accurate and have suggested that the upper limit of normal should be assessed more accurately and revised accordingly[2,3].

There is no study regarding normal level of ALT in Iranian healthy adults at low risk for chronic liver diseases. This information, in addition to daily clinical practice, is specially important and necessary for different research studies of chronic liver diseases in Iran. The aim of this study was to assess the normal value of ALT in a population at low risk for subclinical chronic liver diseases in the capital city of Tehran and to investigate factors associated with abnormal ALT in this population.

MATERIALS AND METHODS

Study population

From March 2001 through April 2002, 1959 apparently healthy blood donors at Tehran Blood Donation Center were randomly recruited into the study. The participants were part of a study for identifying the causes of elevated serum ALT level. After explanation about the objectives of the study and possible necessity for further blood test and follow up, a written informed consent was obtained, and a clinical questionnaire with emphasis on psychosocial and medical history to exclude subjects who were considered the high risk group for blood born infections was completed by a physician interviewer, and serum samples were collected from all consenting subjects. Our study was in accordance with the ethical standards for human experimentation and approved by the Ethical Committee of the Digestive Disease Research Center, Tehran University of Medical Sciences. Body weight and height of all subjects were measured and history of alcohol and drug use was taken.

Laboratory methods

Blood samples were centrifuged within 30 minutes of collection. The biochemistry and virologic tests including hepatitis B s antigen (HBsAg), and hepatitis C virus antibody (HCV Ab), and rapid plasma regain test, and HIV Ab were measured. All tests were performed at Digestive Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran. Analyses of serum ALT levels were performed by using the Hitachi 704 autoanalyser, Tokyo, Japan. The upper limit of normal introduced by manufacturer was 40 U/L for both men and women. Body mass index (BMI) was calculated by dividing the weight (in kg) and the squared height (in meter). We considered a BMI of 24. 9 kg/m² as the upper limit for healthy weight[5].

Definitions of ULN ALT value

Seven methods were used to compare their impact. Method 1: 95^th percentile of ALT distribution regardless of the sex. Method 2: 95^th percentile of ALT distribution after separating males and females. Method 3: a common threshold of 40 IU/L for both males and females proposed by the manufacturer. Method 4: 95^th percentile after separating subjects with body mass index (BMI) under the median which was 27.12. Method 5: 95^th percentile after separating subjects with body mass index (BMI) under 25 -a threshold proposed for separating abnormal and normal weight-[5]. Method 6: 95^th percentile of ALT distribution stratified according to BMI (< 25) and sex. Method 7: 95^th percentile of ALT distribution in each age decade after separating males and females.

Statistical analysis

Statistical analyses were performed by using the SPSS, version 10. 1, software package (SPSS, Inc., Chicago, IL). The 50^th (median), and 95^th percentiles for ALT level were calculated on the basis of the empirical distribution of the data. We set the upper limit for healthy ALT level to the 95 th percentile, as is commonly done for distribution of a continuous variable in the normal population. The univariate associations between factors and ALT expressed in decimal logarithm were assessed by Pearson’s correlation coefficient for quantitative factors and by the Student’s t test for qualitative factors. Multivariate analyses were used to identify factors independently associated with ALT: linear regression, and logistic regression. P values less than 0.05 were considered statistically significant.

RESULTS

Twenty persons were excluded because of positive HBsAg (10 persons), positive HCV Ab (9 persons), or use of alcohol more than 20 grams daily (1 person). Four persons also consumed less than 20 grams per day of alcohol who were included into the study. Thus a total of 1939 persons (1451 males, and 488 females) were included. The characteristics of tested individuals are given in Table . Except one subject who took drugs containing female sex hormones, no body had a history of regular drug usage.

Table 1

Characteristics of 1939 Blood Donors

Factor	Mean	SE
Age (yr)	37.4	0.26
Weight (kg)	79	0.3
Height (cm)	169.96	0.19
BMI (kg/cm²)	27. 35	0.09
ALT (U/L)	19.87	0.27

Correlation between factors and ALT

ALT was significantly correlated with BMI, weight, and height, but was not correlated with age (Table ).

Table 2

Correlation of serum ALT with quantitative clinical factors

Factor	Number	Pearson correlation	P value
BMI	1939	0.125	< 0.001
Weight	1939	0. 17	< 0.001
Height	1939	0.096	< 0.001
Age	1939	0.027	0.23

For qualitative factors (Table ), ALT was higher in males than in females, and ≥ 25 than BMI < 25 in persons with BMI. Association of ALT with BMI was more prominent in men (P < 0.001) than in women (P = 0.025).

Table 3

Serum ALT according to sex, and BMI (lower or higher than 25)

Variable	Count	Mean	SD	P Value
Female	488	16. 4	8.8	< 0.001
Male	1451	21	12.3
All subjects with BMI < 25	563	17.9	10.4	< 0.001
All subjects with BMI ≥ 25	1376	20.7	12.1
Men with BMI < 25	391	19.1	10.8	< 0.001
Men with BMI ≥ 25	1060	21. 7	12.8
Women with BMI < 25	172	15.2	8.8	0.025
Women with BMI ≥ 25	316	17	8.7

Linear regression analysis showed that ALT was independently associated with male sex (Regression coefficient: 4.633, 95%CI: 3.459-5.808, P < 0.0001), and BMI (Regression coefficient: 0.362, 95%CI: 0.237-0.487, P < 0.0001), but not with height, weight, and age.

Also, logistic regression analysis showed that men were 4.57 times more likely to have elevated ALT (ALT > 40) than women (95%CI: 2.1-9.96, P = 0.0001). BMI was also independently associated with elevated ALT (OR: 1.07, 95%CI: 1. 03-1.13, P = 0.004). Age, height, and weight were not found to be related to elevated ALT.

Different definitions of abnormal ALT

The thresholds corresponding to the first six methods to the definition of abnormal ALT are given in Table . The threshold to the definition of abnormal ALT according to method 7 is demonstrated in Figure .

95^th percentile of ALT distribution in each age decade after separating males and females. Note that males over age 70 (41 subjects), and females over age 60 (8 subjects) were omitted from the chart, because of a small number of them.

Table 4

Prevalence among blood donors with normal and abnormal ALT according to the six definitions

Subjects	Method 1:	Method 2:	Method 3:	Method 4: 95^th	Method 5: 95^th	Method 6: 95^th
	95^th percentile	95^th percentile	40 IU/L for	percentile of	percentile of	percentile of ALT
	of ALT distribution	of ALT distribution	both male	ALT distribution	ALT distribution	distribution stratified
	without stratification	stratified according	and female	stratified according	stratified according	according to BMI
		to sex		to BMI (< 27. 1)	to BMI (< 25)	(< 25) and sex
Males	1451	1451	1451	1451	1451	1451
Threshold	40	45	40	39 for BMI ≥ 27.1	39 for BMI < 25	40 for BMI < 25
				41/721	20/391	16/391
				45 for BMI > 27. 1	43 for BMI ≥ 25	46 for BMI ≥ 25
				40/730	65/1060	48/1060
Normal (%)	1363 (94%)	1378 (95%)	1363 (94%)	1370 (94.5%)	1366 (94.1%)	1387 (95.6%)
Abnormal (%)	88 (6%)	73 (5%)	88 (6%)	81 (5.5%)	85 (5.9%)	64 (4. 4%)
Females	488	488	488	488	488	488
Threshold	40	34	40	39 for BMI ≥ 27.1	39 for BMI < 25	34 for BMI < 25
				6/249	4/172	8/172
				45 for BMI > 27. 1	43 for BMI ≥ 25	34 for BMI ≥ 25
				2/239	2/316	15/316
Normal (%)	481 (98.6%)	464 (95%)	481 (98.6%)	480 (98.4%)	482 (98.8%)	465 (95.3%)
Abnormal (%)	7 (1.4%)	24 (5%)	7 (1.4%)	8 (1. 6%)	6 (1.2%)	23 (4. 7%)
All donors	1939	1939	1939	1939	1939	1939
Threshold	40	45 for female	40	39 for BMI ≥ 27.1	39 for BMI < 25	Male: 40 for BMI < 25
		34 for male		45 for BMI > 27.1	43 for BMI ≥ 25	46 for BMI ≥ 25
						Female: 34 for BMI < 25
						34 for BMI ≥ 25

The threshold for ULN ALT varied from 34 U/L (methods 2 and 6 for females) to 46 U/L (method 6 for males with BMI > 25).

The overall median ALT level for the entire study sample was 17 U/L, and the level across the 95^th percentile was 40 U/L. In the 1451 male participants, the median serum ALT level was 18 U/L, and the ALT levels across the 95 th percentile was 45 U/L. The median and 95^th percentiles of ALT level in women were 14 U/L and 34 U/L, respectively. When we considered the population at the lowest risk for liver diseases (persons with negative viral markers, use of alcohol less than 20 g/d, normal BMI, and absence of concurrent medication use), the threshold for abnormal ALT was 40 U/L for men, and 34 U/L for women.

DISCUSSION

This study has identified the factors associated with ALT variability, and determined the thresholds for ALT according to different definitions of ULN ALT. This study further emphasized the findings of previous studies regarding the strong correlation of ALT with sex and BMI[2,3]. This has probably reflected the association between liver steatosis and obesity. The correlation between abnormal ALT and BMI was stronger in men than in women. Additionally, the 95^th percentile of ALT in females with BMI < 25 was equal to females with BMI ≥ 25. This may be due to the fact that the waist to hip ratio (WHR) is higher in men than in women, and non-alcoholic fatty liver disease (NAFLD) is associated with central obesity and higher WHR[5]. WHR was correlated with visceral adipose tissue, which provided a greater supply of potentially hepatotoxic fatty acids to the liver[6].

Our study had some limitations. The study population were apparently healthy blood donors. They could have other unknown factors associated with ALT and they might not exactly reflect the normal general population. Second, the estimation of alcohol consumption was based only on the interview data and might be inaccurate. Third, we could not measure some paraclinical factors associated with ALT such as serum glucose, triglyceride and cholesterol[2,5].

The ULN ALT may differ from different nations and populations and may be influenced by mean BMI and alcohol usage in different societies.

The 95^th percentile of ALT in overweight and obese persons may be too high to be defined as the threshold for healthy ranges of ALT. We suggest that even in overweight and obese persons healthy ranges of ALT should be defined as in non-overweight persons (40 U/L and 34 U/L in men and in women respectively). Since higher values may be due to liver steatosis which occurs more frequently in obese persons, and thus may be abnormal. Adjustment of ALT for sex but not for BMI has also been proposed previously[1]. It seems necessary to repeat this type of investigations in a population based sample and in different ethnic and nationals in order to check whether the impact of sex and BMI remain consistent and if it is proved to be so, then the laboratories should set different ranges of ALT for male and female independently.

In conclusion, this study has demonstrated a strong impact of sex and BMI on serum ALT level. Furthermore, if these findings are proved by other studies, then the normal range of ALT according to sex should be defined. This is particularly helpful in follow up and therapy of patients with chronic hepatitis and designing research protocols.

References

1. Kaplan MM. Alanine aminotransferase levels: what’s normal? Ann Intern Med. 2002;137:49–51. [PubMed] [Google Scholar]2. Prati D, Taioli E, Zanella A, Della Torre E, Butelli S, Del Vecchio E, Vianello L, Zanuso F, Mozzi F, Milani S, et al. Updated definitions of healthy ranges for serum alanine aminotransferase levels. Ann Intern Med. 2002;137:1–10. [PubMed] [Google Scholar]3. Piton A, Poynard T, Imbert-Bismut F, Khalil L, Delattre J, Pelissier E, Sansonetti N, Opolon P. Factors associated with serum alanine transaminase activity in healthy subjects: consequences for the definition of normal values, for selection of blood donors, and for patients with chronic hepatitis C. MULTIVIRC Group. Hepatology. 1998;27:1213–1219. [PubMed] [Google Scholar]4. Willett WC, Dietz WH, Colditz GA. Guidelines for healthy weight. N Engl J Med. 1999;341:427–434. [PubMed] [Google Scholar]5. Ruhl CE, Everhart JE. Determinants of the association of overweight with elevated serum alanine aminotransferase activity in the United States. Gastroenterology. 2003;124:71–79. [PubMed] [Google Scholar]6. Falck-Ytter Y, Younossi ZM, Marchesini G, McCullough AJ. Clinical features and natural history of nonalcoholic steatosis syndromes. Semin Liver Dis. 2001;21:17–26. [PubMed] [Google Scholar]

Serum activity of alanine aminotransferase (ALT) as an indicator of health and disease – Kim – 2008 – Hepatology

This document presents the official position of the American Association for the Study of Liver Diseases (AASLD) on the application of serum alanine aminotransferase (ALT) activity, based upon an analysis of the currently available scientific data. Its authorship was selected by the Public Policy Committee. The document is fully endorsed by the AASLD Governing Board.

Physicians caring for patients with liver disease, predominantly hepatologists and gastroenterologists, have long been aware that measurements of liver enzyme activities (serum aminotransferases, including ALT [alanine aminotransferase] and AST [asparate amniotransferase]) are critical in the diagnosis and assessment of liver disease. These enzymes were formerly referred to as SGPT and SGOT, respectively. The serum ALT activity (hereafter termed ALT) has been regarded as a reliable and sensitive marker of liver disease. ALT may also be a good indicator of overall health, particularly in the context of obesity, the metabolic syndrome, and presence of cardiovascular disease, as many patients affected by these conditions also are at risk of having non-alcoholic fatty liver disease.

Despite all these considerations, abnormal ALT activity is often ignored or minimized by practitioners as most patients are asymptomatic. Minor elevations are often construed to be clinically insignificant, in part because of lack of a longitudinal perspective about the impact of abnormal ALT on long-term outcome such as end-stage liver disease or premature mortality. This document summarizes the position of the American Association for the Study of Liver Disease regarding ALT and includes review of its physiology, its distribution in health and disease, and its role as a screening and diagnostic test and clinical tool. Specifically, the significance of ALT measurements for determining general health, liver health and liver disease is addressed. The purpose of this document is to reinforce that the significance and etiology of a persistently elevated ALT must be evaluated regardless of the degree of elevation and to examine ALT as a population screening tool for early detection of liver disease.

Physiology of ALT

Alanine aminotransferase (ALT) is an enzyme that catalyzes the transfer of amino groups to form the hepatic metabolite oxaloacetate.1 It is composed of 496 amino acids, which are encoded by a gene located in the long arm of chromosome 8.2, 3 ALT is found abundantly in the cytosol of the hepatocyte. ALT activity in the liver is about 3000 times that of serum activity. Thus, in the case of hepatocellular injury or death, release of ALT from damaged liver cells increases measured ALT activity in the serum. Although it is generally thought to be specific to the liver, it is also found in the kidney, and, in much smaller quantities, in heart and skeletal muscle cells.

ALT released in the blood is catabolized in the liver with a resulting plasma half life of 47 ± 10 hours, which is considerably longer than that of AST (17 ± 5 hours).1 ALT activity varies day to day, by 10% to 30%. Within a given day, there is a significant diurnal variation, with ALT activities being up to 45% higher in the afternoon than in the early morning.4, 5

In acute hepatocellular injury, serum AST levels usually rise immediately, reaching a higher level than ALT initially, due to the higher activity of AST in hepatocytes and its release with liver injury. Within 24 to 48 hours, particularly if ongoing damage occurs, ALT will become higher than AST, because of its longer plasma half-life. In chronic hepatocellular injury, ALT is more commonly elevated than AST; however, as fibrosis progresses, ALT activities typically decline, and the ratio of AST to ALT gradually increases, so that by the time cirrhosis is present, AST is often higher than ALT.6, 7 One notable exception to the predominance of serum ALT activity in chronic liver disease is alcoholic liver disease where AST activity is generally higher than ALT levels.

Abbreviations

AIH, autoimmune hepatitis; ALD, alcoholic liver disease; ALT, alanine aminotransferase; ANA, antinuclear antibofy; AST, aspartate aminotransferase; BMI, body mass index; HBeAg, hepatitis B e antigen; HBV, hepatitis B virus; HDL, high-density lipoprotein; MAST, Michigan alcoholism screening test; NAFLD, non-alcoholic fatty liver disease; SMA, smooth muscle actin; SMR, standardized mortality ratio; ULN, upper limit of normal.

Serum ALT as a Blood Test

ALT measurement affords a readily available, low-cost blood test that is utilized throughout the United States as a tool for detection of liver disease. ALT is a valuable screening test to detect otherwise inapparent liver disease, such as asymptomatic viral hepatitis and non-alcoholic fatty liver disease, both of which represent an epidemic that remains largely undiagnosed in the United States. Apart from liver disease, however, serum ALT activity may be affected by a number of factors not associated with hepatic necrosis. ALT levels differ with gender, with higher values in men than in women.8 Additional factors that affect serum ALT levels include body mass index (BMI) and triglyceride levels, regardless of gender.9-11 Total cholesterol levels and alcohol consumption among men have a positive correlation, whereas smoking, physical activity and age have a negative correlation with ALT levels.11-13 Glucose levels, in women, have a positive correlation with ALT activities, whereas use of oral contraceptives tends to lower ALT values.

Some of these correlations (such as BMI) may be explained by ALT being higher in people with fatty liver disease. Similarly, patients with hyperlipidemia or hyperglycemia may also have fatty liver disease, as a part of the metabolic syndrome. In light of the increasing prevalence of obesity in Americans, the distribution of ALT in the apparently healthy population has changed such that some patients with non-alcoholic fatty liver disease may have ALTs in the normal range as determined by the mean ± 2 standard deviations.9 In response, some physicians have advocated lowering the normal range.8

To the extent that there is a rough correlation between ALT and degree of hepatic inflammation in general, patients with high ALT levels tend to have more severe inflammation in the liver than those with normal ALT values. In contrast, the correlation between ALT and degree of hepatic fibrosis, the parameter that is most relevant to the prognosis of the patient, is not very strong, as exemplified by the common observation that a cirrhotic patient may have normal or only mildly elevated ALT.

ALT as an Indicator of Liver Disease

Since serum ALT levels rise in disease states that cause hepatocellular injury, serum ALT levels can effectively identify an ongoing liver disease process. The probability of clinically significant liver disease increases, particularly if the elevated ALT is associated with symptoms such as fatigue, anorexia or pruritus.

The utility of additional evaluation of a patient with asymptomatic elevation of ALT depends upon the findings of history and physical examination, the length of time that ALT has been elevated and the level of ALT elevation. Whereas one study suggested that the majority of asymptomatic people with elevated ALT do not have significant liver disease, a Scandinavian study of 151 consecutive patients with mild to moderate elevations of serum aminotransferase levels for at least 6 months revealed that liver disease was common.14, 15 Diagnoses included non-alcoholic steatohepatitis and hepatic steatosis (noted in 42%), chronic HCV (15%), alcoholic liver disease (8%) and autoimmune hepatitis, primary biliary cirrhosis and alpha1 antitrypsin deficiency in smaller numbers.

The level of ALT also guides the urgency and extent of further investigation. A serum ALT level less than 5 times the upper limit of the normal range should be rechecked before an extensive work-up is undertaken. If elevated ALT levels are confirmed and if they remain persistently elevated, additional work-up is indicated. ALT levels greater than 5 times the upper limit of the normal range suggest a potentially serious, active liver disease process and work-up should be initiated without waiting to confirm the persistence of abnormal ALT.

ALT levels greater than 15 times the normal range indicate severe acute liver cell injury and evaluation should be initiated immediately. The differential diagnosis for patients with severe acute liver injury (ALT levels >15 times the normal range) is relatively limited. Acute viral hepatitis (A-E), ischemic hepatitis or other vascular disorders such as acute venous outflow occlusion (Budd-Chiari), or toxin-mediated hepatitis should be considered. Acute autoimmune hepatitis, hepatic lymphoma or acute biliary occlusion may also present with highly elevated ALT activity. The diagnosis may be made upon historical grounds [ischemic episode, risk factors of acquisition of viral hepatitis, medication or hepatotoxin exposure (e.g., isoniazid) or overdose (e.g., acetaminophen)]. Blood testing (hepatitis and autoimmune serologies) may be helpful where applicable, whereas abdominal imaging may be helpful in other settings (e.g., venous outflow obstruction, biliary obstruction or abnormal lymphadenopathy).

Non-alcoholic Fatty Liver Disease (NAFLD).

NAFLD is probably the most common cause of abnormal ALT values among US adults and may affect up to 3% of the US population.16, 17 Risk factors for NAFLD include obesity, diabetes and hyperlipidemia.18 Elevated ALT may be a component of the metabolic syndrome, the hallmark of which is insulin resistance, manifested by hyperglycemia, hyperlipidemia, abdominal obesity and hypertension. The role of NAFLD as an increasing threat to public health is highlighted by the well-publicized trend in the proportion of overweight or obese Americans.19 Similarly, the prevalence of the metabolic syndrome is also increasing rapidly.20 In these patients, testing for ALT will facilitate timely diagnosis of NAFLD before irreversible fibrosis of the liver is established. Elevated ALT activities may be the only clue to this entity since there are no definitive blood tests to confirm the diagnosis. Furthermore, patients with high ALT among those with the metabolic syndrome may represent a subgroup with a propensity for systemic inflammation that may, in turn, increase the risk of atherosclerosis, leading to coronary artery or cerebrovascular disease.21

Elevated ALT levels may correlate with the severity of NAFLD. In a study in which 233 morbidly obese women were examined, 60% had some degree of hepatic fibrosis, and the majority of these patients had an elevated ALT value. Twenty-eight percent of patients with mild fibrosis and 68% of patients with advanced fibrosis had raised ALT activity. ALT levels were elevated in only 17% of patients without fibrosis.22 These observations are helpful in correlating elevated ALT with severity of liver damage. Therefore, ALT represents an excellent screening test to detect significant NAFLD.23

Alcoholic Liver Disease (ALD).

ALD remains the most common cause of liver-related morbidity and mortality in the United States.24 In alcoholic liver injury, AST activity is characteristically elevated in comparison to ALT activity, although mild elevation of ALT level is common.25 This is thought to be due to the longer half-life of mitochondrial AST released in response to alcohol and the coexistence of deficiency of pyridoxal-6-phosphate in alcoholics, which is a cofactor for the enzymatic activity of ALT.26 History of alcohol use should be ascertained by accurate questioning such as with the CAGE questionnaire27 or the MAST (Michigan alcoholism screening test)28 in all patients with serum aminotransferase elevations. Random blood alcohol level is sometimes useful in distinguishing ALD from NAFLD. The histology of ALD may be indistinguishable from that of NAFLD.29

Hepatitis C Virus (HCV) Infection.

Chronic HCV infection is the most common chronic blood-borne infection in the United States, affecting approximately 2% of the population.30, 31 However, ALT levels fluctuate in HCV and values may occasionally fall into the normal range.32 Since HCV infection is frequently asymptomatic, ALT elevations noted upon routine blood testing often stimulate the work-up whereby HCV infection is diagnosed. Sixty-nine percent of 248 asymptomatic blood donors who tested positive for HCV antibody had elevated ALT activity.33 Sixty-eight percent of patients positive for HCV RNA had elevated ALT levels, compared with 17% of those without detectable RNA. Patients with severe liver damage on liver biopsy in this cohort had at least 1 elevated ALT determination. Twenty-nine percent of HCV-infected patients with initially normal ALT values, when followed, will develop persistently elevated ALT levels, and 57% will develop transient elevation in ALT activities within 5 years.34 HCV patients with persistently normal ALT levels (at least 2 normal ALT values within 6 months) are more likely to be females35 and tend to have lower necroinflammatory and fibrosis scores on liver biopsy when compared to similar patients with elevated ALT activities.36, 37 Significant fibrosis was found in 8% to 20% of patients with normal ALT levels compared to 60% of patients with elevated ALT activities. While ALT analysis alone may fail to detect a minority of persons infected with HCV, it is most effective in detecting those persons whose liver disease is more severe. Such a characteristic enhances the value of ALT as a screening tool for detection of clinically important liver disease. Moreover, the sensitivity of ALT analysis can be improved with serial measurements and long-term follow-up.

Hepatitis B Virus (HBV) Infection.

Chronic HBV infection, a common etiology of elevated ALT values worldwide, afflicts at least 1.3 million individuals in the United States.38 Certain risk groups, such as individuals born in endemic countries, with a history of injection drug use, or on hemodialysis, may be identified in whom prevalence of HBV infection is particularly high in the United States.39 Chronic HBV infection is also frequently asymptomatic and is sometimes discovered because of an elevated ALT level identified upon routine blood testing. Among HBV patients, the level of ALT is associated with progression of liver disease and development of morbidity. The cumulative risk of development of complications is highest in patients with ALT values at least 1 to 2 times above the upper limits of normal (ULN).40 Among patients who are hepatitis B e antigen (HBeAg)-positive, ALT is also predictive of the likelihood of HBeAg seroconversion.41 Thus, in HBV patients, ALT is useful not only in determining the presence of significant liver disease and need for treatment but also in gauging the future course in the natural history of the infection.

Drug-Induced Hepatotoxicity.

The use of many medications has been associated with elevated ALT levels.42 Over-the-counter medications and herbal preparations are also implicated. If elevated ALT levels are confirmed, unnecessary medications should be discontinued, and ALT levels should be monitored. If ALT activity remains elevated, other etiologies should be sought. If the medication must be maintained for clinical benefit, ALT activity should be monitored. If ALT values continue to increase or are associated with development of symptoms or alteration of hepatic synthetic function, the offending medication must be discontinued.

Autoimmune and Cholestatic Liver Diseases.

Autoimmune hepatitis (AIH) may also be identified by recognition of mild to moderate elevations of ALT activity.43 Patients may be asymptomatic or have nonspecific symptoms such as fatigue and arthralgias. Once the diagnosis is confirmed with serologic testing such as antinuclear antibody (ANA) and smooth muscle antibody (SMA) and a liver biopsy, immunosuppressive therapy may be considered. Aminotransferase activity plays an important role in determining treatment candidacy and also treatment response in those who undergo immunosuppressive treatment. Although AST activity has been traditionally used in these criteria, ALT activity is important in these management decisions. ALT levels may also be variably elevated in cholestatic hepatic processes such as primary biliary cirrhosis or primary sclerosing cholangitis.44, 45

Metabolic Liver Diseases.

Mild elevations in ALT level may be noted in hereditary hemochromatosis, a relatively common genetic disorder of iron overload in people of Northern European descent.46 Elevated iron saturation and serum ferritin levels are usually present. Homozygosity of the HFE gene mutation (C282Y/C282Y) confirms the diagnosis, although a liver biopsy with iron quantification remains a useful diagnostic procedure to define the extent of liver injury and amount of iron deposition. Liver biopsy is informative in patients with elevated ALT levels, elevated serum iron studies and unremarkable HFE gene testing.47 Symptoms of the disease are not usually noted until the fourth or fifth decade in men and the fifth or sixth decade in women. It is particularly important to identify patients with hemochromatosis early in life, because liver injury can be prevented with periodic therapeutic phlebotomy. Clinical manifestations of disease can be avoided if treatment commences before complications occur. Mild elevations in ALT activity may also identify other less common genetic disorders such as Wilson disease and alpha-1-antitrypsin deficiency.48 Furthermore, mild elevations of ALT levels are also observed in the setting of celiac disease.49

ALT as a Measure of Overall Health and Mortality Risk

While ALT is useful as an initial test in detecting liver disease, emerging data highlight its potential value as a measure of overall health and survival. There is a strong relationship between ALT activity and mortality, even when the life-threatening process does not originate from the liver.

The strongest population-based data to address the association between elevated ALT values and subsequent mortality risk was based on a cohort of participants of a large health insurance program in Korea.50 In this study, there were 142,055 individuals of ages between 35 and 59 years in whom baseline demographic and laboratory data obtained between 1990 and 1992 were available. This cohort was followed up to 2000, when death certificates were used to determine survival and causes of death.

Figure 1 summarizes the impact of different levels of ALT on mortality. In men, 9% of the subjects had ALT ≥ 40 U/L, whereas only 5% of women had ALT ≥ 30 U/L. ALT activity, in men, correlated with higher mortality from all causes and liver disease. As expected, the effect of ALT was much larger on liver-specific mortality. For example, compared to those with ALT < 20 U/L, men with ALT ≥ 100 U/L had 59 times the risk of death from liver disease. In women, a similar trend was seen, but the number of subjects and events in the highest ALT category was small, making the risk estimation in this group imprecise.

Risk of death according to ALT. Mortality risk from all causes of death and from liver disease in men and women is shown.

In the same study, ALT activity correlated with the risk of cardiovascular mortality as well. Compared with those with ALT < 20 U/L, men with ALT ≥ 100 U/L had nearly 3 times the risk of death from cardiovascular causes. A similar trend was suggested in women, but the incidence of cardiovascular events was low, making extrapolation of the data in women more difficult.

A similar analysis has recently been undertaken in Olmsted County, MN.51 Based on a community-wide database, all county residents who had their ALT determined in the calendar year 1995 were identified and followed forward. Of 47,182 county residents who had healthcare encounters in 1995, 6,823 (14.5%) had their ALT measured. Of those, 5,912 had results within normal limits and 911 (13.4%) abnormal. The standardized mortality ratio (SMR) associated with ALT between 1 and 2 times the ULN was 1.21 (P = 0.23), whereas ALT greater than 2 times the ULN was 1.51 (P = 0.02). On the other hand, ALT less than the ULN was associated with lower risk of death than expected (SMR = 0.61, P < 0.01).

The question of ALT being a marker of cardiovascular health has recently been evaluated by Ioannou and coauthors, who used the third National Health and Nutrition Examination Survey to correlate ALT activity and risk of coronary artery disease in the general US population.52 Of 19,620 adult participants in the survey, 8,381 met the eligibility criteria for the study, which consisted of (1) lack of previous myocardial infarction or congestive heart failure and (2) complete laboratory data including ALT activity drawn after at least 8 hours of fasting. Of those, 7,526 did not have hepatitis B or C or history of excessive alcohol use. These included 7,259 subjects whose ALT was within normal limits (≤43 U/L) and 267 who had elevated ALT activities. When these 2 groups were compared to each other, those with elevated ALT activity had higher total cholesterol level, lower high-density lipoprotein (HDL) level, and higher blood pressure and were more likely to be diabetic. These and other risk factors for coronary artery disease were used in a formula (the Framingham Risk Score) to estimate the risk of developing coronary artery disease. Men with elevated ALT levels were estimated to have 1.3-fold increase in the risk of coronary artery disease within 10 years. In women, there was a 2.1-fold increase in risk.

These data highlight that ALT activity is predictive of future mortality in the general population. While mortality may be due to unrecognized liver disease, it may also be related to other risk factors for ALT elevation including obesity, serum cholesterol, and plasma glucose concentration, in addition to alcohol consumption, which are linked to non-liver health risks. The cardiovascular mortality risk associated with ALT activity described may in part be explained by the metabolic syndrome commonly present in patients with non-alcoholic fatty liver disease. Further, ALT may serve as a marker of a proinflammatory state that is associated with higher cardiovascular risk even among individuals with the metabolic syndrome.21, 53

ALT as a Population Screening Test

The biochemical, clinical and epidemiological information presented so far suggest that ALT may be useful as a screening test for early detection of asymptomatic liver disease and possibly for other causes of premature mortality. Screening is defined as the presumptive identification of unrecognized disease by tests, examinations, or other procedures which can be applied easily and conveniently.54 A screening test is not intended to be diagnostic; rather, it is designed to classify individuals with a high probability of disease from those with a low probability. In evaluating a screening test or program, the most widely recognized gauge is the criteria proposed by Wilson and Jungner.55 The following discussion applies the 10 items of the Wilson-Jungner criteria to ALT as a screening test for early detection of liver disease in the population.

1. The Condition Being Screened for Should Be an Important Health Problem.

The primary condition for which ALT is used to screen is chronic liver disease, which may ultimately lead to liver cirrhosis, end-stage liver disease and/or hepatocellular carcinoma. Chronic liver disease is the 10^th leading cause of death in the United States.56 In addition, hepatocellular carcinoma, which almost exclusively occurs in patients with chronic liver disease, is one of the most common malignancies around the globe.57, 58 It is now well established that the incidence of and mortality from HCC in the United States has been increasing in the recent past, further highlighting the importance of chronic liver disease as a public health problem.59-61

2. The Natural History of the Condition Should Be Well Understood.

Progression of chronic liver disease is correlated with accumulation of hepatic fibrosis, eventually leading to cirrhosis, although the rate at which this progression occurs varies by the specific liver disease and by individual patients.62 Clinicians use diagnostic tests to evaluate the degree of fibrosis, which has most commonly been a liver biopsy, although noninvasive methods for this assessment are increasingly being developed. These techniques help clinicians gauge the progression of disease in individual patients.

3. There Should Be a Detectable Early Stage.

In most chronic liver disease, the disease span between the onset of disease and end-stage liver disease is measured in years and decades. This provides ample opportunities for screening with ALT to detect liver disease in a pre-cirrhotic stage.

4. Treatment at an Early Stage Should Be of More Benefit Than at a Later Stage.

Cirrhosis is known as an irreversible condition. Chronic liver disease amenable to effective therapy may be treated at an early stage to prevent progression to cirrhosis. In certain diseases, such as chronic hepatitis C, patients with advanced fibrosis have poorer response to therapy than in those with earlier stage disease.

5. A Suitable Test Should Be Devised for the Early Stage.

ALT is a suitable test to identify subjects with chronic liver disease in an asymptomatic phase. Most, if not all, chronic liver disease entails a component of hepatic parenchymal inflammation and hepatocellular degeneration, which ALT is thought to represent. Although high quality data to demonstrate the diagnostic accuracy of ALT in the detection of liver disease in the general population are lacking, aforementioned data by Prati or by Kim strongly suggest suitability of ALT as a test to detect chronic liver disease in its early stage.

6. The Test Should Be Acceptable.

As a simple blood test, ALT is as acceptable as many other established tests, such as mammography, colon cancer screening modalities, and serum cholesterol measurement.

7. Intervals for Repeating the Test Should Be Determined.

Patients with chronic liver disease are commonly diagnosed in their middle age or later and ALT testing sometime before the fifth decade of life may identify most asymptomatic patients with liver disease. However, further data are needed to delineate at what age(s) ALT screening must be performed or repeated to optimize the performance of a program of screening using ALT.

8. Adequate Health Service Provision Should Be Made for the Extra Clinical Workload Resulting From Screening.

Presently, elevated serum aminotransferase activities constitute 1 of the most common indications for hepatology or gastroenterology consult. No formal study is available to assess whether sufficient manpower exists to address increased demands that may arise if population-wide screening of ALT were to be instituted. A carefully constructed diagnostic algorithm to identify patients with chronic liver disease that may benefit most from hepatology consultation may alleviate extra clinical workload generated from such a screening program.

9 and 10. The Risks, Both Physical and Psychological, Should Be Less Than the Benefits. The Costs Should Be Balanced Against the Benefits.

These last 2 indicators address the risk–benefit and cost-effectiveness ratios of ALT as a screening test. Given its low cost and absence in general of immediate prospect for morbidity and mortality associated with abnormal ALT, the physical and psychological risks and economic costs of an ALT-based screening program likely compare favorably against the benefits of early diagnosis of chronic liver disease. However, formal studies assessing the risk–benefit and cost-effectiveness of population screening ALT have not been conducted.

Conclusions

ALT is an integral part of the evaluation of patients with liver disease. Its importance as a screening test for liver disease is highlighted by the fact that most patients with common liver diseases such as viral hepatitis B and C and non-alcoholic fatty liver disease have elevated ALT, even though they remain without symptoms to prompt a medical evaluation. Thus, although the interpretation and practical use of ALT analysis may differ across specific liver disease categories, ALT is a sensitive test to detect individuals with liver disease. The importance of ALT activity as an indicator of liver disease has recently been demonstrated in population-based studies which documented a strong association between ALT and subsequent mortality from liver disease.

Furthermore, emerging data suggest that ALT has a role as a predictor of mortality independent of liver disease. This association is generally construed to signify NAFLD as a component of the metabolic consequences of insulin resistance, which facilitates the development of atherosclerotic cardiovascular disease. ALT activity may be important not only as a marker of liver diseases but also as an indicator of general health.

Overall, although measurement of ALT is commonly performed as a part of the hepatic panel, the significance of this test may have been underestimated. In examining ALT as a screening tool for the population, we found that ALT meets most of the accepted criteria for a screening test. However, additional data will strengthen the rationale and inform optimal implementation of ALT screening. These include determination of the optimal schedule for ALT screening and assessment of the practical impact of its implementation as well as its cost-effectiveness. While we wait for these data, we highlight that ALT is an excellent screening test in individuals at risk of liver disease. Subsequently, an abnormal ALT result, as determined by a properly defined normal range, must trigger an appropriate clinical evaluation.

Acknowledgements

The authors thank the Public Policy Committee of AASLD for the opportunity to contribute to creating this document on its behalf. The committee consisted of Adrian M. Di Bisceglie, MD (Chair), Henry C. Bodenheimer, Jr, MD, Karen L. Lindsay, MD, Hal Yee, MD, John Goss, MD, Lee M. Kaplan, MD, Robert G. Gish, MD, W. Ray Kim, MD, Arun Sanyal, MD (Board Liaison).

References

The reference intervals shown above are known as a harmonised reference interval. This means that eventually all laboratories in Australia will eventually use this same interval so wherever your sample is tested, the reference interval should be the one shown above. Laboratories are in the process of adopting these harmonised intervals so it is possible that the intervals shown on the report of your results for this test may be slightly different until this change is fully adopted. More information can be found under Reference Intervals – An Overview.

Suspected fatty liver disease as based on elevated serum ALT is associated with increased risk of cardiovascular and all-cause mortality (in addition to liver mortality) in adults [78]. Increased cardiovascular risk in individuals with fatty liver can be due to different factors, which include insulin resistance per se, proatherogenic profile, and exposure to higher levels of insulin, glucose, and prooxidative and proinflammatory milieu.

As a consequence of the impaired lipid metabolism and, particularly of the reduced rate of hepatic lipid export, abnormalities in blood lipids, namely hypertriglyceridemia, low High Density Lipoprotein (HDL) concentrations, and small, dense low-density lipoprotein particles are commonly observed in these patients. Elevated triglycerides have been found to be associated with hepatic steatosis in a series of children [10, 74]. Hepatic fat content as measured by using fast Pre-magnetic resonance imaging (MRI) in 49 obese adolescents with normal glucose tolerance was associated with a pronounced dyslipidemic profile characterized by large Very Low Density Lipoprotein (VLDL), small dense Low Density Lipoprotein (LDL), and decreased large HDL concentrations [10]. Also the prevalence of the metabolic syndrome was the highest in the tertile with the highest content of hepatic fat. Studies have demonstrated that children with biopsy-proven NAFLD are more likely to have dyslipidemia, hypertension, insulin resistance, and more components of metabolic syndrome than age/sex/body mass index (BMI)–matched controls without NAFLD [79] and that to have more components of the metabolic syndrome augments the risk for more severe derangement of the hepatic parenchyma [74]. Because fatty liver is constantly characterized by impaired insulin sensitivity and clusters with all the metabolic abnormalities of the metabolic syndrome, it is widely considered the hepatic component of the syndrome [15, 59, 74]. A recent study revised retrospectively data from a hospital-based cohort study. Sixty-six children with NAFLD were followed for up to 20 years. The metabolic syndrome was present in 29% of the children at the time of NAFLD diagnosis, with 83% presenting with at least one feature of the metabolic syndrome including obesity, hypertension, dyslipidemia, or hyperglycemia. Four children with baseline normal fasting glucose developed type 2 diabetes 4 to 11 years after NAFLD diagnosis [9].

In the absence of a larger longitudinal study, it is hard to investigate the relationship between pediatric fatty liver and increased morbidity and mortality from cardiovascular disease. Thus, in a pediatric setting, cardiovascular risk can be predicted indirectly and, for instance, by evaluating vascular reactivity through the measurement of circulating molecules, which can be involved in the disruption of the plaque, or in the monocytes recruitment at the endothelium site, the evaluation of the carotid intima media thickness, the Ankle Brachial Pressure Index (ABPI), or by estimating micro-albuminuria.

A couple of studies have observed higher levels of intima media thickness in children with fatty liver as compared with obese children without fatty liver or normal-weight controls [80, 81]. In our series, carotid intima media thickness did not differ between obese children with and without fatty liver [82]. Furthermore, in a regression model, we tried, but unsuccessfully, to rule out if the relationship between cardiovascular disease and fatty liver could be mediated by reduced levels of adiponectin. Measurement of 24 urinary excretions of albumin also failed to differentiate obese children with fatty liver from those without [83].

The association between fatty liver, prediabetes, or overt diabetes seems more evident. Moderate elevation in alanine aminotransferase levels was found to be associated with high-normal glucose levels [84], whereas abnormal ALT levels were reported in youngsters with type 2 diabetes [85], raising the question of a potential role of fatty liver in the onset of T2DM in obese youth. One study [10] demonstrated that independent of overall obesity, the severity of hepatic steatosis strongly affects the presence of prediabetes and diabetes in obese adolescents. The hepatic content of fat has been estimated by using nuclear magnetic spectroscopy, and patients with a content of fat in the highest tertile of the sample had significantly higher values of 2h plasma glucose. In a large sample of children and adolescents with ultrasonographic evidence of fatty liver, we have observed that subjects with fatty liver have 2h plasma glucose higher than those without and that the mean difference between values in the two groups is 13 mg/dl [86]. Children with fatty liver seem able to compensate with increased beta cell function for reduced insulin sensitivity [10, 86]. In fact, although insulin sensitivity decreases across tertiles of hepatic liver content, beta cell function increases [10].

Creatinine: Creatinine is produced by your muscles as they breakdown creatine, a substance involved in muscle contraction. Creatinine is formed at a constant rate in the body and excreted by the kidneys, so by evaluating the amount of creatinine in your blood, your doctor can determine how efficiently your kidneys are working. Creatinine levels are measured by taking a sample of blood from your vein; then, the concentration of creatinine in your blood is compared to a standard amount for your age and sex. Increased blood creatinine levels may indicate an increase in lupus involvement of the kidney. Other conditions, such as high blood pressure or diabetes, can also cause elevated creatinine levels.
Sometimes individuals are asked to provide a 24-hour urine sample for further assessment. The combination of blood and urine samples can be used to evaluate a creatine clearance—how effectively your kidneys filter small molecules, such as creatinine, from your blood. In addition, since creatinine is usually removed from the blood at a constant rate, blood creatinine levels can be used as a standard by which doctors can compare other urine or blood tests. Your serum (blood) creatinine level can also be combined with your age, weight, and gender to evaluate your estimated glomerular filtration rate (eGFR). Glomeruli are tiny ball-shaped structures in your kidneys that help filter blood and prevent the loss of valuable substances, such as blood cells and proteins. The eGFR is an educated estimate of the amount of blood that is filtered per minute by your glomeruli and is often used to detect kidney damage.
Blood urea nitrogen (BUN): The BUN test measures the amount of urea nitrogen in your blood. The liver produces nitrogen in the form of ammonia (Nh4) as it breaks down proteins into their constituent amino acids. From the liver, urea travels in your blood to the kidneys, which filter the urea and flush it from your body in the form of urine. To evaluate an individual’s BUN level, blood is drawn from the vein, and the concentration of urea nitrogen in the blood is evaluated and compared to a standard value for that person’s age range. Even though increased protein levels in a person’s diet can cause their blood urea nitrogen levels to increase, elevated BUN may suggest kidney involvement due to lupus or another condition such as dehydration that causes decreased blood flow to the kidneys. Low BUN levels are uncommon and are usually not as important; they can suggest certain conditions, such as malnutrition, over-hydration, or liver disease, but doctors usually use other tests to monitor these conditions.

Tests of blood glucose levels are performed to determine if an individual’s blood glucose is in normal range. This test helps to detect hyperglycemia (high blood sugar), hypoglycemia (low blood sugar), and diabetes (which can occur after long-term steroid therapy). Glucose is a simple sugar that your body gets from the food you eat. The cells of your body need glucose to obtain energy, and they cannot function without it. When we think of providing our bodies with energy, we usually think about movement and physical activity. However, glucose is also vital to the cells of your brain and central nervous system.

The amount of glucose in your blood is controlled by a feedback mechanism involving two hormones, insulin and glucagon. These hormones work to ensure that your blood contains the right amount of glucose so that your cells—including those in your brain and central nervous system—can function correctly. When your body takes in glucose after a meal, insulin is secreted by cells in your pancreas (beta cells) in order to lower your blood glucose to the appropriate level. When your blood sugar gets too low, glucagon is secreted by alpha cells of the pancreas in order to raise glucose levels. Disruptions in this feedback mechanism can be harmful to your body. In people with diabetes, the body either does not make enough insulin or does not use it properly. High or low blood sugar levels caused by diabetes or other conditions can be serious if not kept in check.
Blood glucose levels are usually evaluated when the patient is fasting, but they can also be taken at random, after a meal, or in a “challenge” test in which a person consumes a certain amount of glucose to challenge their system and track the way his/her body deals with glucose over time. Diabetics usually monitor their own blood glucose levels at home.

A lipid profile is a group of tests that includes measurements of total cholesterol, HDL-cholesterol (“good cholesterol”), LDL-cholesterol (“bad cholesterol”), and triglycerides (fats), all of which are risk factors for cardiovascular disease. It is important that your doctors perform fasting lipid profiles if your cholesterol has been elevated, because people with lupus are at an increased risk for heart disease. In fact, cardiovascular disease—not lupus itself—is the number one cause of death in people with lupus. Furthermore, medications used in lupus treatment, especially corticosteroids such as prednisone, can raise blood pressure, blood glucose, cholesterol, and triglyceride levels, exacerbating the risk factors for cardiovascular disease in people with lupus.

Total Cholesterol: Cholesterol is a fatty substance made in the body and absorbed from certain foods that is essential in your body’s normal processes. It plays an important role in the membranes of your cells, is used to make hormones, and helps form the bile acids needed for your body to obtain nutrients from food. Your total cholesterol is a measurement of both types of cholesterol—LDL and HDL—and should be below 200 mg/dL. Total cholesterol levels above 240 mg/dL are considered dangerously high, especially in people with additional risk factors for cardiovascular disease, such as smoking, obesity, or family history. If your total cholesterol level is above 200 mg/dL, your doctor will most likely recommend that you follow a diet low in saturated fats and cholesterol and begin a moderate exercise regimen. If diet and exercise alone are not enough to control your cholesterol, she/he may prescribe a medication called a statin to help lower your cholesterol levels.
Low Density Lipoproteins (LDL): Cholesterol circulates in the body in complex molecules called lipoproteins. Low density lipoproteins (LDL) are sometimes known as “bad cholesterol,” because they can deposit excess cholesterol in your arterial walls, restricting blood flow and causing a condition known as atherosclerosis. If arteries become blocked, a person can suffer heart attack, stroke, or other complications. LDL levels above 100 mg/dL are considered to be above the optimal range. If you have other risk factors for heart disease, such as a history of smoking, low HDL levels, high blood pressure, diabetes, or a personal or family history of cardiovascular disease, you should aim for lower LDL levels.

Albumin: Albumin is a small protein made in the liver that constitutes the major protein in blood serum. Albumin performs many functions in your body, including nourishing tissues, transporting various substances through the body (hormones, vitamins, drugs, and ions), and preventing fluid from leaking out of your blood vessels. Albumin concentration will drop if a person suffers from liver damage, kidney disease, malnourishment, serious inflammation, or shock. Abumin levels allow your doctor to assess for or monitor liver or kidney disease due to lupus and other factors.
Total Protein: In addition to albumin, your blood serum also contains a protein called globulin. In fact, globulin is actually a class of proteins that includes enzymes, antibodies, and hundreds of other proteins. A total protein test measures the combined amount of these proteins in your blood. An albumin to globulin (A/G) ratio is also computed. A person’s total protein level gives information about kidney damage, liver damage, and nutritional health. If your total protein falls outside of the normal level, your doctor will most likely order other tests to assess for liver or kidney function.

Electrolytes are ions (electrically charged chemicals) in the blood and other body fluids. The concentration of electrolytes in your body depends on adequate intake of nutrients, proper absorption of nutrients by the intestines, and proper kidney and lung function. Abnormal electrolyte concentrations can indicate abnormalities in certain organs and bodily processes. For example, retention of sodium, bicarbonate, or calcium can indicate problems with kidney function. Hormones also help to control electrolyte concentrations, so abnormal electrolyte levels can also reveal certain hormone deficiencies or problems with certain hormone-regulating glands or organs. Some of the electrolytes measured in a comprehensive metabolic panel are explained below.

Sodium (Na+): Sodium helps to regulate your body’s water balance and plays an important role in proper heart rhythm, blood pressure, blood volume, and brain and nerve function. Hypernatremia refers to having too much sodium in the blood; this can occur, for example, due to a high-salt diet. Too much sodium in your blood can cause high blood pressure, among other things. Hyponatremia refers to having too little sodium in the blood. Hyponatremia can cause confusion, restlessness, anxiety, weakness, and muscle cramps. Sodium levels in the blood are regulated by a hormone called aldosterone that is secreted by the adrenal glands. Aldosterone works to regulate sodium levels by increasing your kidneys’ reabsorption of sodium ions.
Potassium (K+): Potassium plays a role in regulating the acid-base chemistry and water balance in your blood and body tissues. It also helps your body to synthesize proteins and make use of carbohydrates for fuel. Potassium is essential for normal muscle growth and helps sodium and calcium to maintain normal hearth rhythm and regulate the body’s water balance. Potassium also helps your muscles to contract and your nerves to send impulses. Potassium levels may be low if an individual is on a diuretic (fluid pill) such as hydrochlorothiazide (HCTC) or furosemide (Lasix). Blood potassium levels that are too high or low may lead to muscle weakness and cramping; very low levels may cause irregularities in heartbeat. Like sodium levels, potassium levels in the blood are regulated by aldosterone, which promotes potassium loss from your kidneys.
Calcium (Ca2+): Most people recognize calcium as a part of bones and teeth, but calcium plays many other roles in the body, such as regulating heartbeat, transmitting nerve impulses, contracting muscles, and helping blood to clot properly. Blood calcium levels are regulated by parathyroid hormone, which is secreted by the parathyroid gland, and calcitonin, which is secreted by the thyroid gland. Since lupus causes an increased risk of osteoporosis and corticosteroid (e.g., prednisone) use can elevate this risk, most people with lupus should take calcium and vitamin D supplements to help maintain adequate bone density. Medications called bisphosponates may be added to help with bone integrity if osteoporosis is detected. However, it is important that you realize that a blood calcium test measures the amount of calcium in the blood, not the bones. For an adequate measurement of bone health, you will need to obtain a DEXA scan every 2 years.
Carbon dioxide (CO2): This test measures the amount of carbon dioxide (CO2) in the blood, which is present in the form of CO2, bicarbonate (HCO3-), and carbonic acid (h3CO3). These three forms are involved in the equilibrium that maintains the pH of your blood (7.35-7.45). Bicarbonate also works with other electrolytes to maintain a certain charge balance in your cells. The concentration of carbon dioxide in your blood is maintained by your lungs and kidneys. High or low levels of CO2 may prompt your doctor to order other tests to check your kidney and lung function, blood gases, or fluid retention.

Lupus and some of the medications used to treat lupus can affect the liver. In addition, factors such as excessive alcohol intake or viral hepatitis can affect the liver in people with lupus, just as they can in the normal population. Certain tests can be performed as part of a comprehensive metabolic panel to give insight into the function of your liver. In addition, your doctor may order a test called a liver panel if she/he suspects that you have symptoms of a liver disorder. Usually these tests measure certain liver enzymes, namely alkaline phosphatase (ALP), alanine amino transferase (ALT), and aspartate amino transferase (AST). Bilirubin, a waste product of the liver that is stored in the gall bladder, is also measured. These values can be used by your doctor as a screening or monitoring tool for liver involvement. About 30-60% of lupus patients experience abnormal liver function tests; some have no symptoms of liver disorder. Generally, increased levels correlate with increased activity, but other factors can contribute to elevated levels of liver enzymes in the blood. For example, NSAIDs, acetaminophen (Tylenol), and aspirin can cause liver enzyme values to increase, especially in people with lupus. If your doctor notices abnormal liver enzyme levels, she/he may ask you to undergo additional tests for hepatitis.

Alkaline phosphatase (ALP): Alkaline phosphatase (ALP) is an enzyme—a protein that helps to bring about chemical reactions in your body—found mainly in your liver and bones. High levels of ALP in the blood may indicate bone or liver abnormalities. If high ALP values are accompanied by high values of other liver enzymes and bilirubin, then the test suggests liver involvement. Certain ratios of liver enzymes can also indicate more specific conditions. Children usually have higher ALP levels than adults because their bones are still growing.
Aspartate amino transferase (AST): Aspartame amino transferase (AST) is an enzyme found mainly in the liver, heart, and muscles. AST is released into the blood by injured liver or muscle cells but is used primarily to detect liver damage. [Another enzyme called creatine kinase (CK or CPK) is a better indicator of heart or muscle damage.] Levels of AST are usually viewed alongside other liver enzymes to assess for liver damage. Like ALT, very high levels of AST may suggest acute hepatitis.
Bilirubin: Bilirubin is a yellow-brown substance formed when the liver breaks down old red blood cells. Too much bilirubin can be a sign that the liver cannot adequately remove bilirubin from the system due to blockage (e.g., gallstones, tumors), cirrhosis, or acute hepatitis. Elevated bilirubin can also indicate hemolytic anemia, a reduction in red blood cells due to abnormal breakdown of red blood cells (hemolysis). Hemolytic anemia can be inherited or acquired; about 10-15% of people with lupus develop autoimmune hemolytic anemia. Hemolytic anemia causes red blood cells to have a shortened lifespan in the blood, and since bilirubin is a product of old red blood cells, it accumulates in the body faster than it can be eliminated. [Other tests called the Coombs test, haptoglobin count, and reticulocyte count are better diagnostic tests for hemolytic anemia.] Several inherited conditions, such as Gilbert’s syndrome, can also cause a person to have too much bilirubin. These conditions may be serious or benign. Often a buildup of bilirbubin is accompanied by a yellowing of the skin called jaundice.

The thyroid is a gland in your neck associated with your metabolism—the processes by which your body makes use of energy. Autoimmune thyroid disease can occur in people with lupus, as can other thyroid conditions. Usually, thyroid conditions cause the gland to release too much or too little hormone. Your doctor may order tests to detect the level of thyroid hormones in the blood, especially if you experience significant weight loss or gain, sweating, acute sensitivity to hot or cold, fatigue, or other symptoms. These tests can also help your doctor monitor the effectiveness of thyroid treatment. Tests for thyroid hormones are explained below in greater detail. Your doctor may request additional tests, such as tests for thyroid antibodies, to learn more about your condition.

Thyroid stimulating hormone (TSH): Thyroid stimulating hormone (TSH) is a hormone released by the pituitary gland that signals the thyroid to release its hormones (T3 and T4) when levels in the blood get low. Together, TSH, T3, and T4 are part of a negative feedback loop that keeps levels of thyroid hormones constant in the blood. Abnormal levels of TSH in the blood can suggest a problem with the pituitary gland, such as a tumor, but this is unlikely. More often, high or low TSH levels indicate problems with the thyroid gland. The thyroid may not be responding to stimulation by TSH, or it may be releasing too much T3 and T4. Underactive thyroid (hypothyroidism) is more common in lupus, but overactive thyroid (hyperthyroidism) can also occur. Both of these conditions can be dangerous if not properly treated.

Leukocytes are formed from bone marrow stem cells.They do not live long, so they are constantly renewed. The production of white blood cells in the bone marrow increases in response to any tissue damage, which is part of the normal inflammatory response. Different types of leukocytes have slightly different functions, but they are capable of coordinated interactions by “communicating” with the use of certain substances – cytokines.

For a long time, the leukocyte formula was calculated manually, however, modern analyzers allow much more accurate research in automatic mode (the doctor looks at 100-200 cells, the analyzer – several thousand).If the analyzer detects atypical cell forms or significant deviations from the reference values are detected, then the leukocyte formula is supplemented by microscopic examination of a blood smear, which makes it possible to diagnose some diseases, such as, for example, infectious mononucleosis, to determine the severity of the infectious process, to describe the type of atypical cells detected in leukemia …

Neutrophils – the most abundant of the leukocytes – are the first to fight infection and are the first to appear at the site of tissue damage.Neutrophils have a nucleus divided into several segments, therefore they are also called segmented neutrophils or polymorphonuclear leukocytes. These names, however, refer only to mature neutrophils. Ripening forms (juvenile, stab) contain a whole core.

Lymphocytes are one of the most important parts of the immune system, they are of great importance in the destruction of viruses and the fight against chronic infection.There are two types of lymphocytes – T and B (in the leukocyte formula for counting the types of leukocytes separately). B-lymphocytes produce antibodies – special proteins that bind to foreign proteins (antigens) on the surface of viruses, bacteria, fungi, protozoa. The antibody-surrounded cells containing antigens are available to neutrophils and monocytes, which kill them. T lymphocytes are able to destroy infected cells and prevent the spread of infection. They also recognize and destroy cancer cells.

There are not very many monocytes in the body, but they carry out an extremely important function. After a short circulation in the bloodstream (20-40 hours), they move to tissues, where they turn into macrophages. Macrophages are able to destroy cells, just like neutrophils, and keep foreign proteins on their surface, to which lymphocytes react. They play a role in maintaining inflammation in some chronic inflammatory diseases such as rheumatoid arthritis.

Age	Reference values
Less than 1 year	16 – 45%
1-2 years	90 126 28 – 48%
2-4 years	32 – 55%
4-6 years	32 – 58%
6-8 years	90 126 38 – 60%
8-10 years	90 126 41 – 60%
10-16 years	43 – 60%
Over 16 years	90 126 47 – 72%

Most often, the level of neutrophils is increased in acute bacterial and fungal infections.Sometimes, in response to infection, the production of neutrophils increases so significantly that immature forms of neutrophils enter the bloodstream, and the number of stabs increases. This is called a shift in the leukocyte count to the left and indicates the activity of the bone marrow response to infection.
There is also a shift of the leukocyte formula to the right, when the number of stab forms decreases and the number of segmented ones increases. This happens with megaloblastic anemias, liver and kidney diseases.

oncological diseases of the bone marrow and metastases of other tumors in the bone marrow.9 / l
Lymphocytes,%
Age
Reference values 
Less than 1 year
45 – 75%
1-2 years
37 – 60%
2-4 years
33 – 55%
4-6 years
33 – 50%
6-8 years
30 – 50%
8-10 years
90 126 30 – 46%
10-16 years
30 – 45%
Over 16 years
19 – 37%
Causes of increased lymphocyte count:
infectious mononucleosis and other viral infections (cytomegalovirus, rubella, chickenpox, toxoplasmosis),
some bacterial infections (tuberculosis, whooping cough),
oncological diseases of the bone marrow (chronic lymphocytic leukemia) and lymph nodes (non-Hodgkin’s lymphoma). 9 / l
Monocytes,%
Age
Reference values 
Less than 1 year
4 – 10%
1 – 2 years
3 – 10%
Over 2 years
3 – 12%
The reasons for the increase in the level of monocytes:
acute bacterial infections,
tuberculosis,
subacute bacterial endocarditis,
syphilis,
oncological diseases of the bone marrow and lymph nodes,
cancer of the stomach, mammary glands, ovaries,
connective tissue diseases,
sarcoidosis.9 / l
Eosinophils,%
Age
Reference values 
Less than 1 year
1 – 6%
1 – 2 years
1 – 7%
2 – 4 years
1 – 6%
Over 4 years
1 – 5%
Most common causes of increased eosinophil levels:
allergic diseases (bronchial asthma, hay fever, food allergies, eczema),
infestation with parasitic worms,
allergic reactions to drugs (antibiotics, allopurinol, heparin, propranolol, etc.)).
More rare reasons for their increase:
Lefleur’s syndrome,
hypereosinophilic syndrome,
systemic connective tissue diseases,
oncological diseases of the bone marrow and lymph nodes.
The number of eosinophils may decrease at:
acute bacterial infections,
Cushing’s syndrome,
Goodpasture syndrome,
taking prednisone.9 / l.
Basophils,%: 0 – 1.2%.
An increase in the content of basophils is rare: in cancer of the bone marrow and lymph nodes, polycythemia vera, allergic diseases.
The number of basophils can decrease in the acute phase of infection, hyperthyroidism, long-term therapy with corticosteroids (prednisolone).
Leukocytes
Leukocytes are blood cells whose main function is to fight infectious agents.
Determination of the number of erythrocytes is an integral part of the leukocyte formula and is not performed separately.9 / l (10 in st. 9 / l).
What is this analysis used for?
To detect infection, inflammation or cancer – their presence is indicated by an increase in the number of leukocytes. A significant decrease in their number may indicate a decrease in immunity.
When is the study scheduled?
In case of suspicion of infection, inflammation or conditions in which the number of leukocytes changes, as well as to monitor the effectiveness of treatment of such diseases.
Which biomaterial can be used for research?
Venous or capillary blood.
General information about the study
Leukocytes are blood cells that are formed in the bone marrow. Their main function is to fight infection and tissue damage. There are five types of leukocytes, which differ in appearance and functions: eosinophils, basophils, neutrophils, lymphocytes and monocytes. They are present in the body in relatively stable proportions and, although their numbers can vary significantly during the day, they normally remain within the reference values.
Leukocytes are formed from stem cells of the bone marrow and in the process of maturation go through a number of intermediate stages, during which the cell and the nucleus contained in it are reduced. Only mature leukocytes should enter the bloodstream. They do not live long, so there is a constant renewal of them. The production of white blood cells in the bone marrow increases in response to any tissue damage, which is part of the normal inflammatory response. The purpose of the inflammatory response is to delimit damage, remove the causative factor that caused it, and restore tissue.
Different types of leukocytes have slightly different functions, but they are capable of coordinated interactions with the use of certain substances – cytokines.
A significant increase in the number of leukocytes (over 100 x 10 ¹² / l) can make the blood more viscous, which can lead to headaches, increased blood pressure and visual disturbances. If the number of neutrophilic leukocytes decreases and becomes less than 1 x 10 ¹² / l, then the risk of infections increases, their course becomes more severe.In this case, the infection can be caused by microbes that are normally “friendly” to the body.
What is it used for and When is the study ordered?
This test is usually part of a routine complete blood count.
An increase in the number of leukocytes (leukocytosis) helps to identify infection and inflammation.
A significant increase in the number of leukocytes (more than 50-100 thousand x 10 ¹² / l), as a rule, indicates a malignant tumor of the bone marrow and requires urgent medical attention.
A decrease in the number of leukocytes (leukopenia) is much less common than leukocytosis. It most often indicates a viral infection, but it can be a sign of more dangerous diseases such as AIDS or aplastic anemia.
The use of radiation therapy or some drugs (in particular, cytostatics) can lead to a decrease in the number of leukocytes, so their number is monitored for timely correction of therapy.
Among other things, this study is being conducted in the treatment of leukemia to assess the effectiveness of therapy.9 / l
1-2 years
Platelets
Platelets are blood cells whose main function is to participate in blood coagulation.
Russian synonyms
Plaques, Bizzozero plaque.
Synonyms English
Platelet Count, Thrombocyte, Thrombocyte count, PLT.
Units
* 10 ⁹ / l (10 in st.9 / l).
What is this analysis used for?
For the detection of clotting disorders or bone marrow diseases.
When is the study scheduled?
With a general blood test, which is necessary for various reasons.
In cases of unexplained or prolonged bleeding.
When diagnosing a bone marrow disease or monitoring its course.
What biomaterial can be used for research?
Venous or capillary blood.
General information about the study
Platelets, like other blood cells, are formed in the bone marrow. Some stem cells in the bone marrow are converted into megakaryocytes, from which platelets are “cleaved” and released into the blood. They are devoid of a nucleus and are relatively small in size (2-3 microns in diameter); they are the smallest blood cells.
Damage to the vessel causes the formation of substances that convert platelets into an active form. Platelets flatten and gain the ability to adhere to each other and to the vessel wall, creating a blood clot that helps stop bleeding.
The life span of platelets is about 10 days, so their constant renewal is required. If there is no balance between the formation of platelets in the bone marrow and destruction, there may be a tendency to increased bleeding or, conversely, to thrombus formation.
During the analysis, the number of platelets in a blood unit is counted – in a liter or in a microliter.
What is the research used for?
The need to determine the number of platelets, as well as their functionality may arise in case of clotting disorders or diseases of the bone marrow, such as leukemia (and if they are suspected).
When is the study scheduled?
Calculation of the number of platelets, as a rule, is included in the routine general blood test, which is carried out both routinely and for various diseases and pathological conditions, before surgical interventions.
This test is prescribed for patients suffering from unexplained bruising, excess blood during menstruation, bleeding gums, nosebleeds, or those who bleed from a small wound for a long time.9 / l
A significant increase in the number of platelets (more than 1 billion per liter (1000 * 10 ⁹ / L) contributes to their more active “sticking” and thrombus formation. In adults, the normal number of platelets ranges from 150 to 450 million per liter of blood (150-450 * 10 ⁹ / L). If they become less than 20 million per liter (20 * 10 ⁹ / L), this can lead to spontaneous bleeding and threaten a person’s life. Decrease in platelets to less than 5 million per liter (5 * 10 ⁹ / l) with a high probability will lead to death.
Causes of increased platelet count
Malignant formations in the bone marrow (myeloproliferative diseases) and in other organs.
Polycythemia vera.
Iron deficiency anemia.
Tuberculosis.
Injuries, acute or chronic infections.
Removal of the spleen (as old platelets are destroyed in it).
Inflammatory bowel disease.
Autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis).
Renal failure.
Severe blood loss.
Reasons for a decrease in platelet count
Decrease in the formation of platelets in the bone marrow.
Increase the rate at which they are destroyed or used.
Immune thrombocytopenic purpura is the most common cause of excessive platelet destruction. In this case, antibodies to their own platelets appear. Antibodies bind to platelets, which causes their rapid destruction, so that their lifespan is reduced to several
Test reference values - how important are they?
The assay reference values or guideline values are the limits within which the test results are considered normal for a healthy person.They can be expressed either by a specific range of numerical parameters in which the result should fall, or have the answer “positive” or “negative”. For example, a “negative” response to a study for the presence of chlamydia in the body is considered a reference value. The reference values for different types of examinations may differ in interval depending on the gender of the patient, as well as on the age. For example, the reference interval for hemoglobin levels in men is slightly higher than in women. And a number of biochemical blood parameters in children are very different from those of adults.
Tests in women for hormones have different reference indicators, depending on the day of the menstrual cycle, as well as age-related physiological changes.
How are test reference values determined?
The reference values are determined as a numerical interval “from” and “to”, after carrying out special test analyzes among a group of healthy people. To the average statistical indicator for each group of patients (by sex and age), a statistical indicator is added and subtracted – twice the standard deviation.Thus, an interval of reference values is formed.
On the forms for issuing test results, as a rule, reference indicators are printed next to the actual result. Sometimes the actual results of laboratory tests fall outside the range of standard values, which causes anxiety for the patient. However, do not forget that the result of the study can be influenced by a lot of factors that, in the patient’s opinion, are insignificant, and which he did not mention during the tests.Proper preparation for the delivery of tests plays an important role in the accuracy of laboratory tests.
The result of the study should be interpreted only by a doctor, taking into account all the characteristics of the patient – his physical condition, taking medications, chronic diseases, age, gender, place of work, physical activity, type of diet, stress in the patient’s life, etc. Any deviations of the research results from the standard values are a reason to conduct more detailed examinations of the patient! Only a doctor, based on the tests done, can prescribe additional studies, as well as therapy.
It should not be discarded the fact that for some patients, exceeding the analysis result of reference values is the norm, due to its physiological characteristics. But whether this is true or not, only a doctor can say, on the basis of monitoring the patient’s test analyzes and a complete examination of his physical condition.
90,000 What is really worth fearing about AI? / Habr
Ah, you are my darling. How can you not look at you like a piece of shit?
A long time ago, in the far, far away city of Kharkov, I was 7 years old.In those days, for the first time in my life, I saw a new miracle of technology – a VHS player. In my hands I had my first cassette in my life. It didn’t really matter to me what I watched. What was important was the very fact that I would be able to see something in the recording. Not knowing what fate awaited me, I shoved a cassette with a painted pen with the inscription: “Terminator 2” into the tape recorder.
They say that children still have imagination. And they know how to imagine better than adults. I don’t know why, but the best thing I remember is the scene in which Los Angeles is bombarded with nuclear warheads.I was in a panic horror, quietly sat in front of the “video recorder” and rewound the tape back to once again see these, which seemed so scary at that time.
After I woke up, I started asking adults about what I had just seen, when it would happen, and whose fault it would happen. They snorted at me and told me not to worry.
And they were right. I have matured. Terminator 2 has ceased to be just a scary movie, and turned into a masterpiece that I remember from childhood.And the fear about artificial intelligence has ceased to bother me, having replaced itself with the fear of human intelligence.
And really, what is there to be afraid of? Automatic nuclear bombing? Killer drones from dystopian YouTube videos? Another spin-off of the same Terminator? Or worse, the awful Robocop reboot? No, the future is not inhabited by walking cyborg killers, despite all attempts by Keanu Reeves and Harrison Ford to show us November 2019.
And how did it happen that a long time ago, in a distant galaxy, there was no artificial intelligence, except for drones stuffed with gears? And in the distant future, in 20,000 years, according to Frank Herbert, the death penalty will be relied on for the creation of artificial intelligence.
And life, nevertheless, continues. Life, it is right here and now. And people quietly begin to lose their temper, because we get too much of this AI. And we still can’t agree on what to do with it. Someone says that it needs to be eradicated, but Mark Zuckerberg says that there is nothing better than teaching the same AI to work better.
Here’s another point of view. When I asked my friends about this point of view, I found out that most people have a strange guess about it, but rarely express it out loud.
Your main mistake is that you think computers can think.
There is such a wonderful word in the English language “misnomer”. It translates into Russian as “misuse of the word.” A long time ago, when the first lamps in ENIAC or UNIVAC were just warming up, the American warriors who built these computers in the 45th year decided to call their brainchildren “Electronic Brains”.
And here there was a mess and complete chaos. No one, in principle, in those ancient times had any idea about how the brain works.As a matter of fact, even now no one can tell anything about it normally. We have neurons, they are intertwined together, and you get, Vasya Pupkin. Well, we think so. When you think, electricity flows through your brain. And when you don’t think, you don’t have it. There is also a joke in the fact that you memorize in the brain. But we don’t know how. Probably, neurons are somehow intertwined. If we count these neurons, it turns out that we do not know how we can remember anything at all. By the way, here’s another thing. There are people who you hit on the head with your finger and they will forget themselves.And there are those who chop off half a brain with an ax, and everything will be fine.
No, seriously. Let’s not say that we fully understand how the brain works. We understand in the same sense as we understand the work of the heart. We have 4 cameras. Blood goes here, flows from here to here, here’s the systolic pressure, here’s the diastolic pressure. If everything is really bad, we can put a pacemaker on the heart. In general, we understand how it works. But, commands to the heart come from the brain, but for this we do not undertake to answer.This is the part of the brain that is beyond the control of humans. It is impossible to control it. Unless, only you are not some Indian magician. They can, but they can do a lot.
Yes, we have neuro-interfaces, we can do tomograms and cut out tumors. We know that Vasya Pupkin is not a lodger without a brain. But we don’t know how it actually works.
Why? Because we don’t know how to make a new brain.
If we know how the Soviet radio “Radiotekhnika” works, we understand the purpose of all its parts and can assemble a new “Radiotekhnika”.We can fix Radio Engineering. We can build “Radiotekhnika” on a transistor microcircuit from China, on transistors and on good warm lamps. This means that we really understand what “Radiotekhnika” is and how this receiver works.
Brain? No. We have suspicions, but we are not sure yet. In 1945, we generally had no idea about 90% of the information that we know about the brain today.
And now, having such knowledge, someone comes and says: “You know, dear sirs, I thought so, we need to call this thing“ Electronic Brain ””!
Misnomer.Incorrect use of the word.
And everything would be fine, but someone was fooled. Since the name contains the word “brain”, then the computer is the brain. And away we go. We have programmers who understand how computers work, and there are some sectarians who are trying to recreate the brain, hoping to make it alive and think independently.
Let’s put some things on the shelves
AI decided that this is the most suitable picture for this title. Enjoy a visual representation of bubble sort.
So let’s start with the definitions.
First, let’s omit what is written in Wikipedia. This is more like the terror flying on the wings of the night.
Let’s better go to the Merriam-Webster dictionary.
Full Definition of artificial intelligence
1: a branch of computer science dealing with the simulation of intelligent behavior in computers
2: the capability of a machine to imitate intelligent human behavior
Full definition of the phrase artificial intelligence:
“The branch of computer science that simulates intelligent behavior in computers.
The Ability of a Machine to Imitate Reasonable Human Behavior. ”
We don’t need to invent anything else. Here is the answer to the question, what is AI. This is imitation of human behavior by a machine. If you have any idea that this has something to do with the creation of life – go see the definition of the word “imitation”.
Accordingly, the first chess program may be called AI. Krivorukaya, but still imitation.
Now that we have this definition at hand, we can move on to more specific definitions.For example, we can look at the concept of machine learning:
Definition of machine learning
The process by which a computer is able to improve its own performance (as in analyzing image files) by continuously incorporating new data into an existing statistical model.
The branch of computer science dealing with the creating and use of computer software that employs machine learning.
Translated into Russian:
The process by which a computer is able to improve performance (such as in the recognition of graphic files) by continually adding new data to an already existing statistical model.
A computer science branch that develops and implements software that uses machine learning.
So machine learning is just adding data to the statistical model. What do we get at the output of your ML network? long value in the range from 0 to 1. You are either looking at a dog, then it is .999 dog, or you are seeing a cat. It will be .998 cat. Or, if the system is very confident, you can get 1 dog. This is 100% the dog in the picture, I give a tooth.The complication of these algorithms allows you to create interesting things. For example, we can make the computer play Mario. Or fold the figures in Tetris. Position 1 is 10% good and position 2 is 78% good.
And then as in “Futurama”:
– Nice, isn’t it?
– Of course, but this is only 93% of your beauty.
– Oh Bender! It’s either a miscalculation or you’re the most romantic robot I’ve ever met!
Love is evil – you will love Bender too.
Well, for the beauty of the soul, we can look at the “Neural Network”.
A computer architecture in which a number of processors are interconnected in a manner suggestive of the connections between neurons in a human brain and which is able to learn by a process of trial and error.
A computer architecture in which processors (computing cores) are interconnected in the same way, similar to how neurons in the human brain are connected. This architecture can learn by trial and error.
Total: We have an architecture in which we connected processors in a certain way, and we can do “machine learning” on it.
Again, none of the above suggests a substitute for a brain or intelligence.
So what are you complaining about, author?
That we love to burn witches at the stake and play ghost hunters. Perhaps because there is a lot of science fiction, or perhaps because we misunderstand something, we begin to attribute human feelings to machines.
And I’m not saying that we are trying to create a system that will make judgments about the launch of nuclear warheads. No. We didn’t do such a stupid thing.
Instead, we do other stupid things.
We have entrusted the AI with our emotions and the ability to choose.
Every time we swipe up in Tik-Tok, like in Insta, or spin a feed on Facebook, we trust artificial intelligence in choosing the next material so that we can do something. then take.
Something that has always been the lot of human decisions has been left to computers. Because we simply cannot physically process so much information correctly.
In the good old days we had bards, jesters, storytellers, ringleaders and the like. Their job was to entertain us. When such a person goes on stage (or starts talking with friends) he is able to analyze the atmosphere and understand what is happening. If he blurts out something out of place, then he can analyze the situation, think about it and, based on his experience, make a decision about what to say next.
If Luda didn’t like the joke about pink pants and a unicorn, then a good storyteller will remember that Luda is mean, but Luda likes cats. Therefore, he will switch the topic to cats. And everything can go well.
When our Algorithm offers us the next video to watch, it is not your best friend who can understand and forgive you. His job is not to make you feel better. Its task is to make you stay on the site longer. And so, your gaze lingered on some strange video, and the Algorithm has already made a decision about what is good and what is bad.Three hours later, you find yourself in a swamp of some strange videos about the death of animals on the roads.
Don’t get me wrong,
There is nothing wrong with AI itself. If only you accept “him” for who “he” is. This is a computer algorithm. A sequence of actions to find the result. In this case, the result will not be clearly defined, but this is the goal of the AI. Find the most correct possible result from the most correct set of data.
What influences the work of AI? Input data and model.Who trains this model and collects the data? Human.
There is always a person behind any device.
A machine can never be the cause of something new. Someone is the cause of anything at all in life, not something. Even if someone builds a machine that “thinks” and “creates a better machine,” it is because someone has created a machine that creates machines.
And further, in front of you is the situation with firearms. Give two people pistols. The first man will be a seasoned fighter who fired hundreds of different weapons.Let the second be a kid who knows nothing about weapons, but watched films about brothers.
The first, most likely, will put the gun on safety, and take away from sin. The second one will shoot something. The first person knows what he has done, what is in his hands and how to use it. The first person is responsible for what is in his hands. The second person will shoot the neighbor’s cat and say: “I am not to blame, it is itself.”
The analogy with automobiles would be much better.You saw the same hardened carrier, who calmly sits in a traffic jam. He knows that if you rock the boat now, you will only waste time and gasoline. He knows how the machine works and how the movement occurs. His car is already 10 years old, but there is not a scratch on it, and the motor works as it should. There is always enough fresh oil in it. And the battery terminals are cleaned to a shine.
On the other hand, we have a standard fefa that pours oil into the washer funnel.
The first man is that strange, endangered breed of professionals in their field.These are people who can be responsible for the result of their actions. The second breed is our self-taught programmers who have watched the course “How to write neurons in 3 hours on“ YouTube ”.
The responsible programmer will sit down and will use the neural network to recover blurred images. The second person will write a chat bot to cheer up himself and his friends.
What is the difference?
The first one understands that AI is just an algorithm that allows you to effectively solve problems with an indefinite answer.
The second – thinks that AI is some kind of consciousness that makes decisions better than a person.
AI does not make decisions better than a human
Another picture found by search engines based on the text of this article.
He accepts them 91,482 faster than people. In a given dataset, a well-trained network can find the most correct answer much more productively than a human. Processing an array with more than a thousand parameters is something that will take Vasya Pupkin 200 years for manual calculations.
The ability to quickly sort images, follow certain instructions, or even drive a car is something that AI will do well. We have a certain amount of strict rules that limit the scope of activity, and in this amount we can teach our AI to make decisions based on data from the environment.
Know what the AI can’t do? He cannot create. He will not be able to start new ideas. An algorithm that performs certain actions to obtain the final result will not be able to say to itself at one fine moment: “Fuck it all! I’ll go, gentlemen, to Vatutinki, and it all failed.I will build a house, I will grow carrots! ”
And if you naively believe that AI can do something like that, because someone just wrote AI that creates new works of art, then you are deeply mistaken. Because someone wrote this new AI.
To create something new we need you – an abstract person. A person who can do an incredible thing that does not obey any laws of physics. A person can take a thought out of nowhere.It just appears and exists. Out of the void.
We don’t have a random number generator in our brains. We do not need to drain manna from heaven over HTTP to suddenly jump up and say, “Oh! Cool! Do you know what I came up with? ”
And honestly, you don’t know how it works. Neurosurgeons don’t know how it works. Psychologists don’t know how it works. It just works. Therefore, we, as engineers, can safely leave this aside. This is not in our area of expertise.It works, and let it work.
But, as engineers, we must understand what is in our area of expertise.
Artificial intelligence algorithms are well suited for automating tasks that cannot be automated with a well-defined sequence of actions. Image processing, anomaly detection, price and performance analysis are what we should get into while training AI.
But, certain things are too tough for artificial intelligence.The opportunity to suggest what I should watch after I finish watching the whole Game of Thrones, I’d rather leave to my friends. The answer to the question: “What suits me better with dark pants, a gray or white T-shirt?” is a question that only three people in my life can answer.
What’s the problem?
There is such a wonderful name in English, Karen, which is used for all dim mothers. There are equivalents in Russian. You can recall the classics – Ellochka.
The problem is that with the help of AI, you can not take responsibility for your actions. And people use this to cover up their own shortcomings.
Remember when I talked about professionals? My grandmother was an architect. She spent all her life in front of a piece of Whatman paper with a slide rule in her hands. She knew the strength of materials in a way that I never dreamed of. When she entered a fashionable new building, she always critically examined the supporting structure, and several times expressed her opinion in front of me. “This will hold” or “Interesting solution, but it would probably be worth putting something thicker.”
A professional in his field differs from a non-professional in that he can achieve the result that is required of him.
If you are a professional architect, you must be able to design sustainable structures.
If you are a professional programmer, then you should be able to write good, robust, optimized code that gives answers and doesn’t crash.
If you are an attorney, you will be required to provide the correct advice and references to current legislation to resolve existing differences.
If you are an opera singer, then you should be able to hit the right notes at the right time and do it right.
Professionals can do their job and are proud of it.
People who are far from this will invent excuses why they cannot write the code or sing the C sharp in the third octave. And here neural networks and AI came to the rescue.
We got market data from this model, but they were inaccurate, so our sales collapsed.
We were unable to properly limit the content of Internet posts, and our entire social network was suddenly filled with drug propaganda.
Apparently, someone does not know how to do their job. And it hides behind a neuron, because it’s very easy to blame the computer. The computer will not respond to charges. You can always start retraining him. The funny thing is that something can only happen thanks to a person. The computer won’t do anything new.
Only now your work won’t get any better. And the bosses are in charge. It’s so convenient to blame the algorithm. It didn’t work, let’s all sit down and redo the algorithm.
And instead of ripping apart the sales department, and forcing people in this department to solve their problems, and start selling the product, we will sit and write a new algorithm, which is already applied in the wrong place, and which it couldn’t get any better from this rewriting.
Well, and welcome to our Brave New World!
When something doesn’t work out for us, we push AI there indiscriminately. And if it does not work, then we will unscrew the nuts for this AI. And after that we will go to the US Congress, the House of Representatives in the UK or the Parliament in Russia to make excuses and talk about the fact that we taught our social network to neutralize terrorist propaganda, but it turned out, as always.
Computers can’t make human decisions
Don’t you believe? Then go and have some more of these soft French cakes and some tea.
And in order to create, “Inception” or “Argument” you need Christopher Nolan.
And what will the end of our civilization look like?
We will simply fence ourselves off from taking responsibility for anything at all, by setting AI on everything that is possible.
I already imagine such nonsense as the AI justice system.Where you have no idea why decisions are made. You will have an AI system that will tell you how to spend your time correctly. Not how you want to spend your time, but how the average person spends time.
We already have an AI system that tells everyone what movie to watch. Therefore, everyone is flocking to the latest Star Wars, which is simply a bunch of scenes generated from Big Data collected from all the fans. Nor does anyone know about Full Moon Kingdom, a great comedy in which Bruce Willis and Edward Norton play two dads who are preoccupied with the fate of one orphan.
We have AI systems for listening to music, which will undoubtedly lead us to a list of our favorite songs, or better yet, the list of songs that are best selling at the moment.
We already have an AI system that tells us who to fall in love with and how to correspond.
We have an AI system that allows us to find the best candidates for the job. Therefore, candidates with the names of porn stars on their resume undoubtedly crawl out to the top, since the resume is SEO-optimized.
And the day is not so far when we can stop being responsible for our lives, and let them be torn apart by the Algorithm. You don’t need any T-1000 or octopus robots. Nobody will come for you. You will be invited. You will have a promotional brochure in your hands that will tell you that living in the Meta universe is much more convenient. You will be sold the idea that you don’t care what kind of house you have. You can simply load the house that the Algorithm will offer you. He knows. And you don’t know anymore, because you have disaccustomed to making decisions yourself.
Remember, computers work with numbers. They know how to answer the questions “How much”, “How fast”, “How much”. Quantitative responses are those responses that are handled well by various models.
Computers cannot answer the questions “How beautiful”, “How do you like” and “How do you think”.
Don’t be 93% better than Bender Rodriguez.
TL; DR
AI is just an algorithm. He fulfills his goal. Despite the best efforts of certain people, he will always be 91,482 imitations of people.
Problems begin when not too distant amateurs hide behind AI and, due to their ignorance and inability to do something, they simply shift all responsibility for some area of activity to AI.
And then we cannot make ends meet.
Your opinion is important to me
I am working on a project that I call “Rise of Men Against Machines”. Your point of view is important to me. To the author of the most popular commentary on the topic – poke karma and money for beer on paper.
PS. I spoke with one of my editors yesterday. The sudden problem was that there was a 6000 character text. And you needed 10,000 characters. Auto-generation systems could not produce anything normal. I completed the missing 4000 characters in 20 minutes.
This text, 22000 characters, I wrote in 2.5 hours. I just had an idea to write a text about AI, and I wrote it.
I don’t believe in AI systems for text generation. And if you want to write articles, then I recommend that you do not believe in them either.
PPS. Right after I posted this, I saw a new article from @xlebanet https://habr.com/en/post/586794/. Another example of how things can go wrong.
comics, GIF animation, video, the best intellectual humor.
How to run a marathon and not die. A beginner’s guide.
Hello everyone.
The other day I passed my first marathon, which took place on November 7 in Istanbul. After several months of active preparation, I was still able to do it for a pretty good time, as for a beginner.( For 3:43:57 from scratch, without moms, dads and loans ). The reason why I decided to write a post is that in the CIS countries there is absolutely no so-called “running culture”. Especially watching healthy people ruin their health, you understand that few people know about the technique, benefits, dangers, pros and cons of running. And having collected my not great but still experience, I decided to write this post. I want this “informational guide” to be useful for beginner and amateur runners and to save expensive reactors from a bunch of mistakes that can ruin your health at the beginning of your running “career”.The information will also be useful not only for people who want to run a marathon, but also for those who just want to be healthy, lose a couple of kilos and be in good shape.
And so, let’s run …
Since the approaches for passing long distances will be described below, these recommendations are not suitable for people who want to run sprints.
In fact, the distance of 42.2 km is not as terrible as it seems at first glance. The average person can prepare for a marathon in 3-6 months.Most importantly, this can be done without much suffering and exhausting training. At the age of 30+, 4 months from scratch was enough for me. And “from scratch,” I mean, before preparing for a marathon, even running 10 km in an hour was difficult. The main problem of preparation is to avoid a series of mistakes that can stop the runner at the beginning of the path. We will naturally start with the most common things that a novice athlete does.
1. In training, you should run as fast as you can.
And this is probably the biggest and most basic problem for beginners, and perhaps even runners with experience.
As it happens most often.
We go to training, we start running at such a speed that drooling from the mouth spreads over our entire face, after 5 minutes we begin to suffocate, after jogging, leg pain, shortness of breath, snot flowing, I’m in a state of being hit by a train. Then with a happy face we go home, thinking “ how well I trained today, No pain, no gain motherfucker !! “. At the next training session, realizing what suffering awaits us again, we go already with a lack of desire to run.So two or three weeks and people forget to run. They say “ well, obviously running is not my ”. Even if a newly minted runner is enough for half a year of such a “run”, then progress is not very active, the speed and distance does not grow very much, training greatly depletes morally and physically, and this already kills motivation even more. And believe me, reactor resident, I went through this myself and I know what I’m talking about.
But what to do, what to do?
What is the essence: In order to run fast, you must learn to run slowly.Approximately 85% (100% for beginners) of training should be done at a slow pace. A slow pace is considered to be such a pace at which you can safely run 40 minutes or more ( For example, the maximum distance of such a run for me was 54 km and took about 7 hours, but this training was something like a challenge and was not included in my plan initially ), without shortness of breath while calmly talking in related sentences. Also, the heart rate should not exceed 60-70% of your maximum heart rate.(The pulse will be lower) Such a run will perfectly prepare the body of a novice runner for loads and help to avoid injuries, damage to ligaments and joints. “Slow” running is different for everyone. For some it may be 5 minutes per kilometer, and for some it may be 10 and depends on the runner’s basic training. I will also add that even for professional athletes, slow training accounts for 70-80% of the training plan.
2. Ignoring heart rate zones and heart rate.
This error is no longer as fun as we would like it to be.I think that everyone heard that at the next race someone finished the race ahead of time and went to the morgue. The essence of this problem most often lies in the fact that amateur runners do not know what heart rate is and how to work with it. By training incorrectly for a long time, the runners develop heart defects and finish in the next race in Valhalla. And here people are embarrassed. Like “how did Vitka die in the race and his neighbor, Uncle Grisha, has been drinking all his life and alive!” . Although it would seem to us all our lives they say that running helps to train our heart.
What is the essence: First of all, we need to understand that if we want to run and be healthy, then running in training, at a pulse rate of 170 for an hour or even more, will not help us in this. Although the heart is a powerful muscle, it also has its own resource. And our task is to increase it, not decrease it. And work in low to medium heart rate zones is great for this.
How to define these zones and what are they all about?
Quite simple. Heart rate zones are essentially a percentage of your maximum heart rate.There are 5 of them in total. You can calculate your personal heart rate zones using any online calculator upon request in the search engine -> “calculate pulse zones”. ( In general, online calculators are not always accurate and for more accuracy you need to take a test on a gas analyzer, but these calculations using online calculator formulas are suitable for most people) We are interested in heart rate zones 1-2. For example, for me at the age of 31 and the resting heart rate is 54 beats / min, the upper edge of the 2nd zone will be about 135 beats / min.Knowing these data, you can already build a training plan or just go for jogging calmly.
I would also like to stop and briefly analyze the advantages of this approach.
– Running at a low heart rate is safe. The chance of developing heart problems is minimal
– This is the most optimal pulse for fat burning.
– It is the work in the low heart rate zone that best trains your heart, stretching it to its full amplitude, thereby increasing the heart in volume.
– After training at a low heart rate, you will not feel tired.For example, it was quite normal for me to go to the gym or to the pool after a run. Since there was a lot of strength left after an hour and a half running training
3. Cadence.
“What? What is this anyway?” – This is the one I hear most often from runners in the park asking “what cadence they train in.” At best, someone knows that such a concept exists at all. (But I will say right away that this is a controversial topic and there are a lot of supporters and opponents of cadence networks. But since you understand that I am still a “supporter”, I will tell you about it) Cadence is a parameter of the frequency of movement of your legs over a period of time.The optimal cadence is 180 steps per minute. I want to note right away that pace, speed, terrain or some other parameters should not affect your cadence while running. You can run both fast and slow with the same cadence.
“Why do you need it?”
What is the essence: The task of the runner is not only to train the legs and heart, but also to make your running technique more economical and safer. The fact is that beginner runners make large amplitude steps in their technique, with an average cadence of about 140-160.But since each step during running creates an additional load in the form of hitting the ground, which is several times higher than when walking, this load goes to the knees, back, ligaments, and sometimes internal organs. Hence, a large number of myths grow that running kills the knees, and this is true if you run with a low cadence. Also, a low cadence most likely indicates that the legs when running are put in front of themselves and slow down the runner. An optimal cadence will make your run safer by keeping your feet free of shock.
And a fucking story from myself on this topic. 2 years ago I was diagnosed with gonarthrosis of the second stage on two knees, given injections of hilauron, which helped for a short time, they said that the third stage would already be and everything would be bad and there could be no question of running. But after the correct setting of the run and cadence, the degradation of the joint slowed down, and in general, knee pains have not bothered for a year now, and according to the latest MRI, everything is fine. As I was told by some sports doctors with whom I consulted, in the West it is a frequent practice to use walking and running as part of the treatment for knee problems, since under gentle exertion, the knees themselves produce the right amount of synovial fluid that works as a lubricant in the joints.And the right cadence will help with this. But I cannot say that this recommendation is right for you; on this issue it is better to consult with good specialists.
Thanks to everyone who read to the end, I hope this information was useful and helps to avoid problems. If this post was interesting to someone, then I can continue this section, and tell a lot of information about running.
What a runner can eat, food, sports nutrition, etc. Alcohol, smoking, junk food and the effect on the body. (Lovers of beer and wine can breathe a sigh of relief) Alternatives on the run. (Yes, there is such a thing) Clothes and devices for your training. (No brand advertising, etc.) Running along with other sports (Rocking chair, bike, swimming pool, etc. and how to combine it) Duration of training, running volumes, training plans, how to combine work, personal life and running Myths about running How to start running from scratch (Even if in my whole life I went no further than to the refrigerator)
If possible, I can answer questions on this topic in the comments.

Blood test alt normal range. Understanding ALT Levels: Normal Ranges, Causes of Elevation, and Health Implications

What is ALT and Why is it Important?

Normal ALT Ranges: What the Research Shows

Why are gender-specific ranges important?

Factors Influencing ALT Levels

Causes of Elevated ALT Levels

How high do ALT levels need to be to indicate a problem?

ALT and Liver Disease Diagnosis

What other tests are used alongside ALT?

Monitoring ALT Levels in Chronic Liver Conditions

How often should ALT be monitored in chronic liver diseases?

Lifestyle Factors and ALT Levels

Can dietary supplements help lower ALT levels?

Future Directions in ALT Research and Clinical Practice

How might AI and machine learning impact ALT interpretation?

Healthy ranges of serum alanine aminotransferase levels in Iranian blood donors

Abstract

INTRODUCTION

MATERIALS AND METHODS

Study population

Laboratory methods

Definitions of ULN ALT value

Statistical analysis

RESULTS

Table 1

Correlation between factors and ALT

Table 2

Table 3

Different definitions of abnormal ALT

Table 4

DISCUSSION

References

Serum activity of alanine aminotransferase (ALT) as an indicator of health and disease – Kim – 2008 – Hepatology

Physiology of ALT

Abbreviations

Serum ALT as a Blood Test

ALT as an Indicator of Liver Disease

Non-alcoholic Fatty Liver Disease (NAFLD).

Alcoholic Liver Disease (ALD).

Hepatitis C Virus (HCV) Infection.

Hepatitis B Virus (HBV) Infection.

Drug-Induced Hepatotoxicity.

Autoimmune and Cholestatic Liver Diseases.

Metabolic Liver Diseases.

ALT as a Measure of Overall Health and Mortality Risk

ALT as a Population Screening Test

1. The Condition Being Screened for Should Be an Important Health Problem.

2. The Natural History of the Condition Should Be Well Understood.

3. There Should Be a Detectable Early Stage.

4. Treatment at an Early Stage Should Be of More Benefit Than at a Later Stage.

5. A Suitable Test Should Be Devised for the Early Stage.

6. The Test Should Be Acceptable.

7. Intervals for Repeating the Test Should Be Determined.

8. Adequate Health Service Provision Should Be Made for the Extra Clinical Workload Resulting From Screening.

9 and 10. The Risks, Both Physical and Psychological, Should Be Less Than the Benefits. The Costs Should Be Balanced Against the Benefits.

Conclusions

Acknowledgements

Alanine aminotransferase (ALT) – Lab Tests Online AU

How is it used?

When is it requested?

What does the test result mean?

Reference Intervals

Adult

Is there anything else I should know?

Alanine Aminotransferase Blood Level – an overview

Fatty Liver, Cardiovascular Disease, and type 2 Diabetes

Alanine transaminase (ALT) blood test | Multimedia Encyclopedia | Health Information

How the Test is Performed

How to Prepare for the Test

How the Test will Feel

Why the Test is Performed

Normal Results

What Abnormal Results Mean

Risks

References

Blood Chemistry Panel : Johns Hopkins Lupus Center

Kidney Function Tests

Blood Glucose (Sugar) Test

Fasting Lipid Profile

Protein