Hypovitaminosis D as a Risk Factor for Irritable Bowel Syndrome in Individuals With Medically Complicated Obesity

Abstract

Introduction: The prevalence of irritable bowel syndrome (IBS) is reported to be 12% in the general US population, but we have previously reported that 30% of obese individuals seeking bariatric surgery have IBS based on the Manning criteria. This high prevalence of IBS was not related to diabetes mellitus or obstructive sleep apnea. Obese individuals seeking bariatric surgery are known to have a high prevalence of hypovitaminosis D. A cross-sectional study of 12,594 patients reported that hypovitaminosis D was associated with depressive symptoms (Hoang et al, 2011). The use of antidepressants improves global symptoms of IBS (Xie et al, 2015). Based on these findings, the hypothesis of this study is that IBS is associated with hypovitaminosis D in individuals with medically-complicated obesity. Methods: This is a retrospective study in a large, urban community hospital of electronic charts of 271 individuals seen in bariatric gastrointestinal clinic from 2010 to 2012 for preoperative evaluation. The presence of irritable bowel syndrome (IBS) is assessed after asking all individuals to complete a survey of the 6 Manning criteria (IBS is defined by ≥3 criteria). Results: Subjects are excluded (n=42; 15 or 36% with 3-6 Manning criteria; 27 with 0-2 Manning criteria) who did not complete their testing for 25-hydroxy total vitamin D. Among the remaining 229 subjects (80% women, 20% men; 67% Black Americans, 31% Caucasians; Age range: 23-73 years; BMI range: 35-91 kg/m2), 67 or 29% have 3-6 Manning criteria. A total of 180 subjects (79% of 229) have a prior or present low blood level of 25-hydroxy total vitamin D (0 to 29 ng/ml). There is a significant association (p=.01) between IBS and hypovitaminosis D. Conclusion: This study confirms the high prevalence of IBS in obese individuals seeking bariatric surgery. Our results support a major association between IBS and hypovitaminosis D. The findings are important for clinical gastroenterologists who evaluate gastrointestinal symptoms in individuals with morbid obesity. A further prospective study is required to determine whether Vitamin D supplementation in individuals with medically-complicated obesity and hypovitamosis D is effective for the treatment of symptoms of IBS.Table: Table. Association between IBS and Vitamin D (all subjects)*Table: Table. Association between IBS and Vitamin D (excluding subjects with prior vitamin D deficiency)**