Published online Apr 14, 2019. doi: 10.3748/wjg.v25.i14.1729
Peer-review started: February 18, 2019
First decision: February 26, 2019
Revised: March 11, 2019
Accepted: March 24, 2019
Article in press: March 25, 2019
Published online: April 14, 2019
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.
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.
To investigate the relationship between serum 25-hydroxyvitamin D levels and functional chronic constipation linked to intestinal motility disorders.
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).
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).
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.
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.