Vitamin d causing constipation. Vitamin D Deficiency and Chronic Functional Constipation: Unveiling the Link

24.10.202001.06.2021 by alexxlab

How is vitamin D deficiency related to chronic functional constipation. What are the implications of this connection for digestive health. Can addressing vitamin D levels improve constipation symptoms.

Содержание

The Relationship Between Vitamin D and Chronic Functional Constipation

Chronic functional constipation is a common and often debilitating condition affecting millions worldwide. Recent research has shed light on a surprising connection between this digestive issue and vitamin D deficiency. A prospective case-control study conducted by Panarese et al. has revealed a strong link between low serum 25-hydroxyvitamin D levels and chronic functional constipation associated with intestinal motility disorders.

Key Findings of the Study

Patients with chronic functional constipation had significantly lower 25-hydroxyvitamin D levels compared to healthy subjects
Intestinal motility disorders were associated with vitamin D deficiency
Quality of life and psychological well-being were impaired in patients with constipation and low vitamin D levels

Understanding Intestinal Motility Disorders and Their Impact

Intestinal motility disorders refer to conditions that affect the movement of food and waste through the digestive system. These disorders can lead to chronic functional constipation, causing discomfort and a range of associated symptoms. The study by Panarese et al. employed various diagnostic techniques to assess colonic and oro-cecal transit time in patients with constipation.

Diagnostic Methods Used in the Study

Glucose/lactulose breath tests
Radiopaque markers (multiple capsule techniques)
Wireless motility capsule analysis

These methods allowed researchers to exclude small-intestinal bacterial overgrowth and accurately evaluate intestinal transit times in the study participants.

The Role of Vitamin D in Digestive Health

Vitamin D is primarily known for its role in bone health and calcium absorption. However, emerging research suggests that this crucial nutrient may also play a significant role in digestive health and function. The study’s findings raise important questions about the potential mechanisms through which vitamin D influences intestinal motility and constipation.

Potential Mechanisms of Vitamin D’s Effect on Constipation

Regulation of intestinal muscle contractions
Influence on gut microbiome composition
Modulation of inflammatory responses in the digestive tract
Impact on neurotransmitter function in the enteric nervous system

Quality of Life and Psychological Impact of Chronic Constipation

The study by Panarese et al. went beyond just examining the physiological aspects of constipation. It also investigated the impact of intestinal motility disorders on psychological symptoms and quality of life. The researchers used validated questionnaires to assess these factors in patients with chronic functional constipation.

Questionnaires Used in the Study

Irritable Bowel Syndrome Quality of Life (IBS-QOL)
Short Form Health Survey 12
Hospital Anxiety and Depression Scale 14 (HADS-14 A and HADS-14 D)

The results revealed a significant impairment in all health-related quality of life and psychological tests among patients with intestinal motility disorders and low vitamin D levels. This highlights the far-reaching impact of chronic constipation on overall well-being and mental health.

Implications for Diagnosis and Treatment of Chronic Constipation

The strong association between vitamin D deficiency and chronic functional constipation opens up new avenues for both diagnosis and treatment of this condition. Healthcare providers may need to consider vitamin D levels when evaluating patients with persistent constipation symptoms.

Potential Diagnostic and Treatment Approaches

Routine screening of vitamin D levels in patients with chronic constipation
Vitamin D supplementation as a potential adjunct therapy for constipation
Lifestyle modifications to improve vitamin D status (e.g., sunlight exposure, dietary changes)
Combination of traditional constipation treatments with vitamin D-focused interventions

While more research is needed to establish definitive treatment protocols, addressing vitamin D deficiency could potentially offer relief to many individuals struggling with chronic constipation.

The Broader Implications of Vitamin D Deficiency in Gastrointestinal Health

The link between vitamin D deficiency and chronic functional constipation may be just the tip of the iceberg when it comes to this nutrient’s role in digestive health. Emerging research suggests that vitamin D may have wide-ranging effects on various gastrointestinal conditions and functions.

Future Directions in Research and Clinical Practice

The study by Panarese et al. provides valuable insights into the relationship between vitamin D deficiency and chronic functional constipation. However, it also raises numerous questions and highlights areas for further investigation.

Key Areas for Future Research

Longitudinal studies to establish causality between vitamin D deficiency and constipation
Clinical trials evaluating the effectiveness of vitamin D supplementation in treating chronic constipation
Investigation of optimal vitamin D levels for maintaining healthy intestinal motility
Exploration of potential genetic factors influencing the relationship between vitamin D and digestive function
Development of targeted therapies combining vitamin D with other treatments for constipation

As our understanding of the role of vitamin D in digestive health grows, it may lead to significant changes in how we approach the diagnosis and treatment of chronic functional constipation and other gastrointestinal disorders.

Practical Considerations for Patients and Healthcare Providers

The findings of this study have important implications for both individuals suffering from chronic constipation and the healthcare providers treating them. While more research is needed to establish definitive guidelines, there are several practical considerations to keep in mind.

Advice for Patients with Chronic Constipation

Discuss vitamin D testing with your healthcare provider
Consider safe sun exposure and dietary sources of vitamin D
Be aware of potential symptoms of vitamin D deficiency
Maintain open communication with your doctor about constipation symptoms and any changes in your condition

Recommendations for Healthcare Providers

Consider vitamin D screening in patients with persistent constipation
Stay informed about the latest research on vitamin D and digestive health
Evaluate the potential benefits of vitamin D supplementation in constipation treatment plans
Address both the physical and psychological aspects of chronic constipation in patient care

By taking a holistic approach that considers the potential role of vitamin D, healthcare providers may be able to offer more effective and personalized treatments for patients struggling with chronic functional constipation.

The Importance of a Balanced Approach to Vitamin D and Digestive Health

While the connection between vitamin D deficiency and chronic functional constipation is intriguing, it’s essential to maintain a balanced perspective. Vitamin D is just one piece of the complex puzzle of digestive health, and addressing deficiency alone may not be a panacea for all cases of constipation.

Other Factors Influencing Constipation and Digestive Health

Diet and fiber intake
Hydration levels
Physical activity
Stress and psychological factors
Medications and underlying medical conditions
Gut microbiome composition

A comprehensive approach to managing chronic functional constipation should consider all these factors in addition to vitamin D status. Patients and healthcare providers should work together to develop a holistic treatment plan that addresses individual needs and circumstances.

Vitamin D Supplementation: Potential Benefits and Precautions

Given the association between vitamin D deficiency and chronic functional constipation, some individuals may be tempted to start supplementing with high doses of vitamin D. However, it’s crucial to approach supplementation with caution and under medical supervision.

Potential Benefits of Vitamin D Supplementation

Improved intestinal motility
Enhanced overall digestive function
Potential reduction in constipation symptoms
General health benefits beyond digestive function

Precautions and Considerations

Consult with a healthcare provider before starting any supplementation regimen
Determine appropriate dosage based on individual needs and current vitamin D levels
Be aware of potential interactions with other medications or health conditions
Monitor vitamin D levels regularly when supplementing
Consider the balance between vitamin D and other nutrients, such as calcium

While vitamin D supplementation may offer benefits for some individuals with chronic constipation, it’s essential to approach it as part of a comprehensive treatment strategy rather than a standalone solution.

The Global Impact of Vitamin D Deficiency on Digestive Health

The link between vitamin D deficiency and chronic functional constipation may have far-reaching implications on a global scale. Vitamin D deficiency is a widespread issue affecting populations worldwide, particularly in regions with limited sunlight exposure or among individuals with certain dietary restrictions or health conditions.

Factors Contributing to Global Vitamin D Deficiency

Geographic location and latitude
Cultural practices affecting sun exposure
Dietary habits and food fortification policies
Socioeconomic factors influencing access to nutrition and healthcare
Skin pigmentation and its effect on vitamin D synthesis

Understanding the relationship between vitamin D and digestive health could potentially impact public health strategies and nutritional recommendations on a global scale. It may also highlight the need for targeted interventions in populations at high risk for both vitamin D deficiency and chronic constipation.

Integrating Vitamin D Awareness into Digestive Health Education

As the connection between vitamin D and chronic functional constipation becomes more established, there may be a need to integrate this knowledge into broader digestive health education efforts. Both healthcare providers and the general public could benefit from increased awareness of this relationship.

Key Areas for Education and Awareness

The role of vitamin D in overall digestive function
Signs and symptoms of vitamin D deficiency
Natural sources of vitamin D and safe sun exposure practices
The importance of regular check-ups and vitamin D testing
The potential impact of vitamin D on various gastrointestinal conditions

By incorporating vitamin D awareness into digestive health education, we may empower individuals to take a more proactive approach to their gut health and potentially prevent or manage chronic constipation more effectively.

Conclusion: A New Frontier in Understanding and Treating Chronic Constipation

The research conducted by Panarese et al. has opened up a new frontier in our understanding of chronic functional constipation and its relationship to vitamin D deficiency. This connection not only sheds light on potential underlying mechanisms of constipation but also offers new avenues for diagnosis and treatment.

As we continue to explore the complex interplay between vitamin D and digestive health, it’s clear that a multifaceted approach is necessary. Addressing vitamin D deficiency may prove to be an important piece of the puzzle in managing chronic constipation, but it should be considered alongside other established treatments and lifestyle modifications.

The implications of this research extend beyond individual patient care, potentially influencing public health strategies, nutritional recommendations, and our broader understanding of gastrointestinal health. As we move forward, continued research and clinical trials will be crucial in fully elucidating the role of vitamin D in digestive function and developing evidence-based guidelines for its use in treating chronic constipation.

For individuals struggling with chronic functional constipation, these findings offer hope for new and potentially more effective treatment options. As always, it’s essential to work closely with healthcare providers to develop a personalized approach that considers all aspects of digestive health, including vitamin D status.

As our understanding of the intricate relationships between nutrients, gut function, and overall health continues to grow, we may be on the cusp of a new era in digestive health management â€“ one that recognizes the far-reaching impacts of seemingly unrelated factors like vitamin D on our gut function and quality of life.

Chronic functional constipation is strongly linked to vitamin D deficiency

World J Gastroenterol. 2019 Apr 14; 25(14): 1729–1740.

Alba Panarese

Department of Gastroenterology and Digestive Endoscopy, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy. [email protected]

Francesco Pesce

Nephrology section, Department of Emergency and Organ Transplantation, University of Bari, Bari 70013, Italy

Piero Porcelli

Department of Psychological, Health, and Territorial Sciences, D’Annunzio University of Chieti-Pescara, Chieti 70013, Italy

Giuseppe Riezzo

Department of Clinical Pathology, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy

Palma Aurelia Iacovazzi

Department of Clinical Pathology, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy

Carla Maria Leone

Department of Clinical Pathology, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy

Massimo De Carne

Department of Gastroenterology and Digestive Endoscopy, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy

Caterina Mammone Rinaldi

Department of Radiology, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy

Endrit Shahini

Department of Gastroenterology and Digestive Endoscopy, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy

Department of Emergency and Organ Transplantation, University of Bari, Bari 70124, Italy

Alba Panarese, Department of Gastroenterology and Digestive Endoscopy, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy. [email protected];Author contributions: Panarese A has conceived the protocol; Shahini E and Panarese A drafted the initial and final manuscript; Panarese A enrolled patients; Panarese A, and Leone CM collected in a database the baseline and on-treatment information; Shahini E, Pesce F and Porcelli P systematically reviewed the data entries for completeness and consistency, checked for completeness of information and performed the statistical analysis; all the authors reviewed and approved the final draft.

Corresponding author: Alba Panarese, MD, Doctor, Department of Gastroenterology and Digestive Endoscopy, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Turi Street n. 27, Castellana Grotte (Bari) 70013, Italy. [email protected]

Telephone: +39-3471401487; +39-0804994251 Fax: +39-0804994250

Received 2019 Feb 16; Revised 2019 Mar 11; Accepted 2019 Mar 24.

This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial.

This article has been cited by other articles in PMC.

Abstract

BACKGROUND

Few studies have examined intestinal motility disorders, which are disabling conditions associated with chronic functional constipation, whose pathogenesis is actually not well-defined.

AIM

To investigate the relationship between serum 25-hydroxyvitamin D levels and functional chronic constipation associated to intestinal motility disorders.

METHODS

We performed a prospective case-control study, from May-June to November 2017. Glucose/lactulose breath tests, radiopaque markers (multiple capsule techniques) and wireless motility capsule analysis were used to assess colonic and oro-cecal transit time, after excluding small-intestinal bacterial overgrowth condition. Then, we measured 25-hydroxyvitamin D levels in patients with intestinal motility disorders and we further evaluated the influence of intestinal motility disorders on psychological symptoms/quality of life using validated questionnaires, the Irritable Bowel Syndrome Quality of life (IBS-QOL), the Short Form Health Survey 12, and the Hospital Anxiety and Depression Scale 14 (HADS-14 A and HADS-14 D).

RESULTS

We enrolled 86 patients with chronic functional constipation associated to intestinal motility disorders and 86 matched healthy subjects. Patients with intestinal motility disorders had lower 25-hydroxyvitamin D levels (P < 0.001), and they showed a significant impairment of all health-related quality of life and psychological tests (IBS-QOL, Short Form Health Survey 12-Physical Component Summary, Short Form Health Survey 12-Mental Component Summary, HADS-14 A and HADS-14 D), as compared to the control group (P < 0. 001), which significantly correlated with low vitamin D levels (r = – 0.57, P < 0.001; r = 0.21, P = 0.01; r = – 0.48, P < 0.001; r = – 0.57, P < 0.001; r = – 0.29, P < 0.001, respectively). At multivariate analysis vitamin D low levels remained a significant independent risk factor for the occurrence of intestinal motility disorder (odds ratio = 1.19; 95% confidence interval: 1.14-1.26, P < 0.001).

CONCLUSION

Vitamin D deficiency, anxiety and depression symptoms are commonly associated with chronic functional constipation induced by intestinal motility disorders. Vitamin D serum levels should be routinely measured in these patients.

Keywords: Chronic constipation, Intestinal motility, Vitamin D, Quality of life, Anxiety, Depression

Core tip: Intestinal motility disorders, which are disabling conditions associated with chronic constipation, have been examined in only A few studies. Patients with intestinal motility disorders are frequently affected by vitamin D deficiency, which is strongly associated to anxiety, depression symptoms and to severe impairment of quality of life. These data suggest that vitamin D serum levels should be routinely measured, and its supplementation should be evaluated in patients with intestinal motility disorders.

INTRODUCTION

The term “Constipation” has a broad definition both for physicians and patients[1]. The most common form is functional chronic constipation, which is a gastrointestinal disorder defined by symptom criteria, after the exclusion of secondary causes[2-4]. This clinical condition usually affects women, older subjects, particularly those of lower socioeconomic status[5], and has a prevalence ranging between 2% and 27% in western countries with a high burden on global health-care system[2,6,7]. The main symptoms of functional chronic constipation are difficulty with evacuation, bloating, abdominal pain, discomfort or hard stools that significantly impair health-related quality of life[2,8]. Since depression has been commonly observed in patients with the constipation variant of irritable bowel syndrome (IBS), specific questionnaires have been endorsed to evaluate some aspects of the quality of life of these patients, especially the IBS Quality of life (IBS-QOL), the Short Form Health Survey 12 (SF-12), and the Hospital Anxiety and Depression Scale 14 (HADS-14-A/D)[9-12]. Moreover, previous studies showed a possible role of vitamin D deficiency in the pathophysiology of IBS and depression, and also beneficial effects of vitamin D supplementation in alleviating depression and certain gastrointestinal symptoms in a population of study prevalently affected by diarrhea or by alternating subtype, and the minority by constipation symptoms[13-20]. Normal transit constipation is probably the most common form, and it frequently overlaps with the constipation variant of IBS[9].

Among patients with functional chronic constipation, intestinal motility disorders have been reported. Although the overall prevalence of intestinal motility disorders is not currently well-defined[2], it involves more commonly patients affected by slow transit constipation (STC)[2], and rarely subjects with delayed oro-cecal transit time[21], In addition, defecation disorders significantly overlap with normal and STC[9,22]. While STC is characterized by an altered colonic motor activity, and reduced reaction after a meal and when waking up, decreased “high amplitude propagated contractions”, which have been associated to altered regulation of enteric nervous system, reduction of neurons and axons in the myenteric plexus[2,22-24], delayed oro-cecal transit time could be partially associated with an underlying small-intestinal bacterial overgrowth (SIBO)[25].

Moreover, the most severe form of intestinal motility disorder may be considered chronic intestinal pseudo-obstruction, which is a symptomatic and disabling disease, related to a visceral myopathy or/and neuropathy[26]. Hence, colonic transit time could be objectively measured by radiopaque markers (single or multiple capsule techniques), and this diagnostic tool is also used to rule out dyssynergia defecation[2,23]. Radiopaque markers studies are useful, inexpensive and widely available[2,23]. In addition, even if not definitively recommended by guidelines, lactulose breath test (LBT) and glucose breath test (GBT), are commonly used in clinical practice to evaluate the presence of SIBO as well as small-bowel motility by estimating oral-cecal transit time[25,27]. Other expensive tests such as colonic scintigraphy and wireless ingestible motility capsule, measure more accurately overall transit time[23,27], whereas advanced physiologic tests identify anorectal dysfunctions in patients not responding to initial therapy[2,27]. In this paper we hypothesized that serum vitamin D deficiency could be associated with chronic functional constipation secondary to delayed intestinal transit time and consequently we investigated this relationship and the related psychological aspects.

MATERIALS AND METHODS

Study design

This case-control study was performed from May-June to November 2017, in the Outpatients Clinic of our Institution, in Apulia, a Mediterranean region located in southeast of Italy. As shown in Figure , we enrolled 86 subjects from a population of 152 consecutive constipated patients affected by intestinal motility disorders.

Flow diagram describing the process of patients’ selection. CT: Computerized tomography; ROM: Radiopaque markers.

Inclusion criteria were the following: Caucasian subjects ≥ 18 years old, body mass index (BMI) ≥ 18.5 kg/m², affected by functional chronic constipation associated to delayed intestinal transit time, supported by Roma IV criteria[8,26,28]. Exclusion criteria were the following: Subjects > 75 years old, IBS, pregnancy, significant comorbidities such as cardiac, respiratory, chronic renal insufficiency, anorectal and pelvic floor dysfunctions, metabolic/endocrine (diabetes mellitus, hypothyroidism, hypercalcaemia, panhypopituitarism), medications (opiates, antihypertensive agents, iron preparations, anti-epileptic drugs, tryciclic antidepressants, anticholinergics or dopaminergics), organic (extra-intestinal mass, colorectal cancer, ischaemic or surgical stenosis, anal fissure, anal strictures, inflammatory bowel disease, intestinal malabsorption and diverticular diseases), neurological (Parkinson disease, multiple sclerosis, paraplegia, autonomic neuropathy, chronic intestinal pseudo-obstruction, gastroparesis, Hirschsprung disease and stroke), past psychiatric disease, and myogenic (scleroderma, amyloidosis and myotonic dystrophy dermatomyositis)[2,21,26]. In addition, we also assessed a control group of 86 healthy subjects (sex, age and BMI matched), recruited from a population-based cohort study of 150 healthy subjects, which underwent routine clinical exams in our Institute to check their healthy status, after excluding the presence of a functional chronic constipation during the clinical interview.

Our research was carried out in compliance with the Helsinki Declaration and procedures received approval by the Institutional review board of the National Institute of Gastroenterology “S. De Bellis” Research Hospital (0807/16) and by the Research Ethics Committee of the National Oncological Institute of Bari (CAAE:147/16) (Trial registration number: {“type”:”clinical-trial”,”attrs”:{“text”:”NCT03096704″,”term_id”:”NCT03096704″}}NCT03096704). Informed consent was obtained from all participants of the study. The statistical review of the study was performed by a biomedical statistician.

Definition of functional chronic constipation

All selected patients were inquired, before, for any possible secondary causes of functional chronic constipation, including alarm features, lifestyle factors and medical treatments and we also identified the response (or lack of) to previous treatment about constipation symptoms, by interviewing patients. Then, they were considered affected by functional chronic constipation only when they showed a frequency of evacuation less than twice a week with increased stool consistency[8,26,28]. All the selected patients underwent blood tests, colonoscopy, nutritional assessment (with daily food frequency questionnaires), stool frequency diary, LBT, GBT, wireless motility testing, radiopaque markers studies, and when required, tests for pelvic floor dysfunction, and psychological tests exploring patient’s quality of life.

Accordingly, when not eligible, patients were excluded (Figure ): 152 consecutive subjects affected by functional chronic constipation with intestinal motility disorders met the eligibility criteria, along with 150 healthy subjects. Patients and controls in each group were first randomly sampled from the pool of available individuals (152 with intestinal motility disorders and 150 controls) and, then matched for age, sex and BMI, using MatchIt[29]. This analysis resulted in 86 patients and 86 matched controls that were enrolled for the study. Our patients did not receive any pharmacological treatment before all evaluations.

Colonic transit time, breath tests and wireless motility analysis

The colon transit time was measured with radiopaque markers, using multiple capsule techniques (P and A Mauch CH-4142 Munchenstein). The patient ingested 1 capsule a day (at 9.00 am, during breakfast) for 3 consecutive days and each capsule with 24 different shaped radio-opaque polyurethane markers, and then performed abdominal x-rays (100KV) on day 7, at 9.00 am, to reconstruct the colon activity during the last week[30,31]. Normal transit time was considered about 30-40 h, whereas the upper limit, above 70 h. Markers scattered about the colon was due most likely to STC, whereas markers gathered in the recto-sigmoid tract was considered a defecatory disorder[5,27] (Supplementary material).

Moreover, LBT and GBT were used for measuring oro-cecal transit time. A rise in hydrogen of ≥ 20 ppm by 90 min was considered the cut-off value used to exclude SIBO for both tests[25]. Time to the second peak and rise of 5-10 ppm of hydrogen, or a level of positivity for methane ≥ 10 ppm on a breath test, were considered useful in estimating oro-cecal transit time[25,27,32] (Supplementary material). Wireless motility analysis was also used to quantify oro-cecal transit time (Smartpill, Medtronic, Sunnyvale, California, United States), in order to define the presence of a delayed small intestinal transit time. Normal small-bowel transit should be 6 hours or less[25] (Supplementary material). Finally, STC and/or delayed oro-cecal transit time were definitively endorsed when radiopaque markers and/or breath tests with wireless motility analysis identified a specific intestinal motility disorder[27].

Questionnaires for the evaluation of quality of life in patients with intestinal motility disorders

The IBS-QOL questionnaire is a 34-item tool validated to quantify quality of life in non-subtyped IBS patients, but also used to assess the severity of IBS-like symptoms, and psychological factors[10]. The SF-12 includes a subset of 12 items, used to assess the physical and mental health domain in many diseases. All these scores are converted into a standardized 0-100 score. Higher scores indicate a better self-reported health status[11]. Furthermore, the HADS-14 represents a global measure of psychological distress and includes 14 items, 7 of them evaluate anxiety symptoms, and 7 depressive ones. Each item is coded from 0 to 3. The total scores for anxiety and depression can range between 0-21, based on symptoms characteristics[12].

Vitamin D and parathyroid hormone levels measurement

Serum 25-hydroxyvitamin D [25-(OH)-D] (Supplementary material) and parathyroid hormone (PTH) levels were measured in patients and healthy controls within 1 hour from blood draw. Overall subjects were enrolled in the interval time of the year with major sunlight exposition, when 25-(OH)-D values are usually higher[13]. The 25-(OH)-D levels status was categorized as usually proposed by experts in literature: using a standardized cut-off (deficiency less than 20 ng/mL, insufficiency from 20 to 29 ng/mL and sufficient when equal or higher than 30 ng/mL)[13].

Statistical analysis

Screened patients and controls in each group were matched for age, sex and BMI using the nearest neighbor matching algorithm implemented in MatchIt[29]. Normal distribution of continuous variables was assessed with the Shapiro-Wilk test and data were expressed as mean and standard deviation and compared using Student’s t-test. Categorical variables were reported as percentages and compared using the Chi-squared test or Fisher’s exact test, when needed.

Spearman’s test was performed to evaluate possible correlations of vitamin D values with quality of life scores and psychological functions (IBS-QOL, SF12-PCS, SF12-MCS, HADS-14 A and HADS-14 D). The impact of the vitamin D levels on patient’s risk to have intestinal motility disorders was analysed using univariate and multivariate logistic regression analyses. The association between each explanatory variable and the outcome (intestinal motility disorders occurrence) was tested using the likelihood ratio test. We included in the multivariate model all explanatory variables showing a P < 0.05 at univariate analysis. For each variable included in the multivariate model, we calculated both unadjusted and adjusted odds ratios (OR), with their 95% confidence intervals (CI), and the level of significance (using the likelihood ratio test). Statistical significance was set at P < 0.05. All statistical analyses were performed using SPSS 23.0 software (SPSS, Chicago, IL, United States) and R version 3.4.3 (http://www.R-project.org/).

RESULTS

Characteristics of patients with intestinal motility disorders

As shown in Figure , 86 patients along with 86 healthy matched subjects, were finally enrolled. The characteristics of patients are shown in Table . About 85% of patients suffering from intestinal motility disorders were female, and mean age was 49.9 ± 17.4 years. Patients with intestinal motility disorders had significantly lower intermediate and bachelor schooling degree, as compared to the control group (P = 0. 001 and P < 0.001, respectively).

Table 1

Characteristics of patients with functional chronic constipation with intestinal motility disorders and of controls

Variables	Intestinal motility disorders (n = 86)	Controls (n = 86)
Age, mean ± SD , yr	49.9 (17.4)	50 (17.1)
Sex, n (%)
Male	13 (15.1)	13 (15.1)
Female	73 (84.9)	73 (84. 9)
BMI, mean ± SD, kg/m²	23.7 (2.8)	24.6 (3.4)
Education, n (%)
Primary	5 (5.8)	5 (5.8)
Intermediate	33 (38.4)^a	14 (16.3)^a
High school	38 (44.2)	37 (43)
Bachelor degree	10 (11.6)^a	28 (32.6)^a
No data	0	2 (2. 3)
Marital status
Single	30 (34.9)	22 (25.6)
Married	53 (61.6)	58 (67.4)
Widower	3 (3.5)	4 (4.7)
Divorced	0	1 (1.2)
No data	0	1 (1.2)
Symptoms
Constipation	78 (90.1)^a	3 (3.5)^a
Abdominal pain	73 (84. 9)^a	2 (2.3)^a
Swelling	79 (91.9)^a	14 (16)^a
IBS-QOL (total score)	108.4 (23.7)^a	39.8 (7.7)^a
Dysphoria	24.1 (7.7)^a	8.7 (1.5)^a
Interference	15.9 (5.5)^a	8 (1.6)^a
Body image	15 (2.1)^a	4.8 (1.4)^a
Anxiety health	13. 5 (1.8)^a	3.7 (1.4)^a
Food avoidance	13.6 (1.6)^a	3.7 (1.4)^a
Social reaction	10.8 (3.2)^a	5 (1.1)^a
Interpersonal relationships	6.3 (3.3)^a	3.3 (0.6)^a
Sexuality	4.6 (2.2)^a	2 (0.1)^a
HADS-14 A	14.6 (4.3)^a	2.4 (1.8)^a
HADS-14 D	14. 6 (3.1)^a	4.5 (2.6)^a
SF12-PCS	37.3 (9.8)^a	47.2 (7.6)^a
SF12-MCS	29.1 (7.4)^a	56 (7.1)^a
PTH, mean ± SD, 10-70 pg/mL	51.1 (12.1)	–
Vitamin D, mean ± SD, IU/mL	14.6 (7.7)^a	28.4 (8.8)^a

The proportion of patients with intestinal motility disorders was more affected by constipation, abdominal pain, swelling, anxiety and depression symptoms as well as by quality of life alterations, as compared to healthy subjects (P < 0. 001). The results of the various questionnaires compiled by patients (IBS-QOL, HADS-14 A, HADS-14 D, SF12-PCS and SF12-MCS) showed a significant impairment in all health-related domains (P < 0.001) (Table ). Patients with intestinal motility disorders had lower vitamin D serum levels, as compared to the control group (P < 0.001). Moreover, the poor results of psychological tests (IBS-QOL, SF12-PCS, SF12-MCS, HADS-14 A and HADS-14 D) significantly correlated with low vitamin D levels (r = – 0.57, P < 0.001; r = 0.21, P = 0.01; r = – 0.48, P < 0.001; r = – 0.57, P < 0.001; r = – 0.29, P < 0.001, respectively). Other parameters, such as the age, sex and marital status did not differ between the two groups (Table ).

In the groups with intestinal motility disorders, 32, 28 and 26 patients, after completing all diagnostic tests, received a diagnosis of delayed oro-cecal transit time (37. 2%), STC (32.6%) or delayed oro-cecal transit time with STC (30.2%), respectively. In the group with delayed oro-cecal transit time and with STC, the proportion of patients who suffered constipation, swelling, abdominal pain and vitamin D deficiency (< 20 ng/mL) was higher than groups with delayed oro-cecal transit time or with STC (P = 0.03, P = 0.02, P = 0.03 and P = 0.04 respectively) (Figure ). When we considered the three groups: subjects with delayed transit time in both intestinal tracts (26), to patients with delayed transit time in only one tract (60) and to controls (86), the quality of life showed worsening functions. Moreover, vitamin D and BMI were significantly reduced with decreasing values as following for the variables: delayed oro-cecal transit time with STC group less than delayed oro-cecal transit time or STC group, less than controls (P < 0.001, respectively) (Supplementary material).

Proportion of patients who suffered constipation, swelling, abdominal pain and vitamin D serum levels, in delayed small intestinal transit time, slow transit constipation, and delayed small intestinal transit time (with) slow transit constipation groups. STC: Slow transit constipation. Significantly different by ^aP < 0.05.

Patients with delayed transit time of both intestinal tracts, as compared to patients with delayed transit time involving only one tract, showed significantly reduced levels of vitamin D and higher PTH levels (for both P < 0.001), and showed worsening quality of life (P < 0.001) (Supplementary material). Patients with delayed transit time in both intestinal tracts showed significantly reduced serum levels of vitamin D and higher PTH serum levels (for both P < 0.001), and showed worsening quality of life (P < 0.001) than patients with delayed transit time in only one tract (Supplementary material).

Risk factors associated to intestinal motility disorders

Results from linear regression analysis are shown in Table . At univariate and multivariate analysis adjusted for BMI, vitamin D levels remained a significant independent risk factor for intestinal motility disorders occurrence (OR = 1. 19; 95%CI: 1.14-1.26, P < 0.001).

Table 2

Probability of intestinal motility disorder occurrence at the univariate and multivariate analysis

Variable	Univariate analysis		Multivariate analysis
Variable	OR (95%CI)	P value	OR¹(95%CI)	P value
Age, yr	1.0 (0.98-1.01)	0.76	–	–
BMI, kg/m²	0. 91 (0.82-1.0)	0.04	0.98 (0.86-1.11)	0.72
Vitamin D, IU/mL	0.82 (0.78-0.87)	< 0.001	0.83 (0.78-0.87)	< 0.001

DISCUSSION

In this study, we demonstrated for the first time that serum vitamin D deficiency could be associated to functional chronic constipation induced by intestinal motility disorders. Furthermore, patients showing the latter clinical condition are frequently affected by anxiety and depression symptoms which severely impair their quality of life.

About 1 billion people have vitamin D insufficiency or deficiency[13]. Nowadays, this phenomenon is associated with significant disability and healthcare costs[14,15]. Several studies showed that hypovitaminosis D may be a risk factor for many chronic diseases and for mortality[16,33-36]. Notably, vitamin D deficiency has been involved in the pathophysiology of inflammatory bowel disease, IBS and also depression[13-17,19]

Some multicentric studies, reported a higher prevalence of hypovitaminosis D in the southern Europe[37,38]. Interestingly, Italian elderly subjects showed the lowest levels of vitamin D in Europe in the winter season[37,38]. In our study, we found low serum levels of vitamin D, mainly checked during the summer season, among patients affected by intestinal motility disorders during an interval time when vitamin D values are usually high, due to beta-ultraviolet rays exposition[13,36]. Moreover, our patients were prevalently female (84.9%) and relatively younger, although, vitamin D deficiency has not been limited to the elderly age[35-38]. While low levels of vitamin D have been also observed in winter in 33% of pre-menopausal women, especially if obese[39], in our study the majority of patients with intestinal motility disorders had normal BMI.

How vitamin D deficiency and intestinal motility disorders are linked remains an open question. One intriguing hypothesis may be that STC and/or delayed small intestinal transit time could negatively modify the gut microbiota[36], or conversely altered microbiome could primarily affect mucosal barrier and gut motility due to microbial-derived metabolites[40]. In addition, some studies suggested that vitamin D deficiency could predispose to gastrointestinal infections[16], which could be responsible of the “leaky gut” alteration and of loss of immune homeostasis[40,41]. However, in our patients we also performed LBT and GBT, to exclude SIBO. When the clinical suspicion of the latter condition remained, we treated them “ex juvantibus”, and we further excluded SIBO as the main cause of bowel symptoms, especially when they did not disappear after a gut-targeted antibiotic therapeutic cycle.

Anyway, the presence of vitamin D receptor on gut epithelial cells, macrophages and lymphocytes surface, has suggested a possible link between vitamin D deficiency, the dysfunction of its receptor and gut microbiota composition, leading to the onset of autoimmune diseases[40,42,43]. Finally, the influence of vitamin D deficiency on human immune system is also supported by its involvement in the development of multiple sclerosis[44]. As concerning this aspect, an interesting study supported a role of autoantibodies against enteric nervous system targets in B cell-deficient mice with experimental autoimmune encephalomyelitis model of multiple sclerosis, showing that serum immunoreactivity (idiopathically or secondary to another autoimmune disease), could be implicated in the induction of autoimmune gastrointestinal dysmotility[45]. In fact, in humans with multiple sclerosis, whose pathogenesis has been linked to vitamin D deficiency, a slow colonic motility in the proximal tract as well as autonomic rectal dysfunction has been observed[44-48].

We may suppose that the intestinal motility disorder could be the “primum movens” of an underlying autoimmune process in a specific genetic background and unmasked by chronic vitamin D deficiency, which could exert metabolic/immunologic damage on epithelial and neuromuscular structures of the gut. The latter alterations could include gut hyper-permeability and bacterial translocation, whose degree of injury and extension could be influenced by the severity of vitamin D deficiency[22,45]. This hypothesis may be supported by our results, which showed that levels of vitamin D were independently associated with intestinal motility disorders and by the fact that the prevalence of symptoms associated to functional chronic constipation grew up in concordance with the worsening of vitamin D levels, especially in patients involving more extensively the bowel tract. Furthermore, patients with intestinal motility disorders had high levels of psychological distress with impaired quality of life, and hypovitaminosis D significantly correlated with the worsening of the psychological functions. In our study, a potential bias could derive from disease misclassification, which could be a negligible factor since intestinal motility disorder was diagnosed following standardized criteria, and from the small sample size of our population. Moreover, we did not check fecal microbiota composition.

In conclusion, we demonstrated that vitamin D deficiency could be strongly related to intestinal motility disorders. Moreover, patients with intestinal motility disorders are very commonly affected by anxiety and depression symptoms which severely influence their quality of life. If the latter two psychiatric symptoms are caused by intestinal factors, it will be confirmed only through a cross-sectional study. Therefore, we suggest that vitamin D serum levels should be routinely measured and vitamin D supplementation should be considered, to better evaluate its effects on intestinal motility and quality of life of patients with intestinal motility disorders.

ARTICLE HIGHLIGHTS

Research background

Functional chronic constipation is a gastrointestinal disorder that affects more commonly women and older subjects, with a deep impact on global health-care system. Nowadays, only few studies have examined intestinal motility disorders, which are severe clinical conditions associated with chronic functional constipation, whose pathogenesis and prevalence are actually partially known. In this subgroup are inclued patients with slow transit constipation, as well as with slow oro-cecal transit time, whereas their extreme clinical form, could be considered chronic intestinal pseudo-obstruction, which has been related to the structural damage of neural and smooth muscle cells of gut.

Research motivation

Although some studies have shown a possible link between vitamin D deficiency and irritable bowel syndrome (IBS), as well as with depression (and with several other diseases), the same link has never been detected before in patients affected by intestinal motility disorders, and the indications to look for vitamin D in these patients relied only of opinions of experts in the field. Therefore we investigated this relationship and the psychological aspects in this subgroup of patients.

Research objectives

To investigate the relationship between serum 25-hydroxyvitamin D levels and functional chronic constipation linked to intestinal motility disorders.

Research methods

Herein, we applied rigorous statistical methods to elucidate this relationship. We performed a prospective case-control study, from May-June to November 2017. We used Glucose/lactulose breath tests, radiopaque markers (multiple capsule techniques) and wireless motility capsule analysis to estimate both oro-cecal and colonic transit time. After receiving a diagnosis of intestinal motility disorders, patients underwent to blood sampling, for checking 25-hydroxyvitamin D levels. Furthermore, we evaluated for these patients the influence on psychological features and on their quality of life, which were estimated by using validated questionnaires, the IBS Quality of life (IBS-QOL), the Short Form Health Survey 12 (SF-12), and the Hospital Anxiety and Depression Scale 14 (HADS-14 A and HADS-14 D).

Research results

Our cohort included 86 patients with chronic functional constipation associated to intestinal motility disorders and 86 age, sex, body mass index (BMI)-matched healthy subjects. Patients with intestinal motility disorders had lower 25-hydroxyvitamin D levels (P < 0.001), and they showed a significant impairment of all health-related quality of life domains and psychological tests (IBS-QOL, SF12-PCS, SF12-MCS, HADS-14 A and HADS-14 D), as compared to the control group (P < 0.001). Moreover, the latter tests significantly correlated with reduced vitamin D levels (r = – 0.57, P < 0.001; r = 0.21, P = 0.01; r = – 0.48, P < 0.001; r = – 0.57, P < 0.001; r = – 0.29, P < 0.001, respectively). In multivariate analysis, vitamin D low levels remained significantly associated with the occurrence of intestinal motility disorder, after adjusting for BMI (odds ratio = 1.19; 95% confidence interval: 1.14-1.26, P < 0.001).

Research conclusions

We demonstrated for the first time a strong association between vitamin D deficiency and intestinal motility disorders. Moreover, these patients are very commonly affected by anxiety and depression symptoms which deeply impact on their quality of life. These findings suggest that vitamin D serum levels should be routinely measured in this category of patients and consequently vitamin D supplementation could represent a further therapeutic aid for this clinical condition.

Research perspectives

Our findings may confirm how vitamin D deficiency could exert a wide spectrum of action in many gastrointestinal (or not) diseases, being highly associated with intestinal motility disorders and with certain neuropsychiatric symptoms, but remains unclear if it could have a causative role in this process, and for this reason, future cross-sectional studies are needed, also to investigate if anxiety and depression symptoms are caused by intestinal factors.

ACKNOWLEDGEMENTS

We thank to Vanessa Terenzio and Domenico Flavio Terenzio, native English speakers, for the language revision of this manuscript.

Footnotes

Institutional review board statement: National Institute of Gastroenterology “S. De Bellis” Research Hospital (0807/16) and by the Research Ethics Committee of the National Oncological Institute of Bari (CAAE:147/16) (Trial registration number: {“type”:”clinical-trial”,”attrs”:{“text”:”NCT03096704″,”term_id”:”NCT03096704″}}NCT03096704).

Informed consent statement: All study participants or their legal guardian provided informed written consent about personal and medical data collection prior to study enrolment.

Conflict-of-interest statement: All authors declare no conflict of interest related to this publication.

Manuscript source: Invited manuscript

Peer-review started: February 18, 2019

First decision: February 26, 2019

Article in press: March 25, 2019

Specialty type: Gastroenterology and hepatology

Country of origin: Italy

Peer-review report classification

Grade A (Excellent): 0

Grade B (Very good): B, B

Grade C (Good): C

Grade D (Fair): 0

Grade E (Poor): 0

STROBE statement: The guidelines of the STROBE Statement have been adopted.

P-Reviewer: Feretis M, Luthin DR, Negreanu L S-Editor: Yan JP L-Editor: A E-Editor: Song H

Contributor Information

Francesco Pesce, Nephrology section, Department of Emergency and Organ Transplantation, University of Bari, Bari 70013, Italy.

Piero Porcelli, Department of Psychological, Health, and Territorial Sciences, D’Annunzio University of Chieti-Pescara, Chieti 70013, Italy.

Giuseppe Riezzo, Department of Clinical Pathology, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy.

Palma Aurelia Iacovazzi, Department of Clinical Pathology, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy.

Carla Maria Leone, Department of Clinical Pathology, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy.

Massimo De Carne, Department of Gastroenterology and Digestive Endoscopy, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy.

Caterina Mammone Rinaldi, Department of Radiology, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy.

Endrit Shahini, Department of Gastroenterology and Digestive Endoscopy, Scientific Institute for Digestive Disease “Saverio de Bellis” Hospital, Castellana Grotte (Bari) 70013, Italy. Department of Emergency and Organ Transplantation, University of Bari, Bari 70124, Italy.

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