Physical activity in relation to irritable bowel syndrome among Iranian adults

BACKGROUND: Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal disorder worldwide. Physical activity in relation to IBS has been investigated in few studies and data in this regard are conflicting. AIM: To investigate the association between physical activity and IBS in a large sample of Iranian adults. METHODS: This cross-sectional study was done on 4763 Iranian adults in the framework of SEPAHAN (The Study on the Epidemiology of Psycho-Alimentary Health and Nutrition) project. The physical activity of study participants was assessed using the General Practice Physical Activity Questionnaire (GPPAQ). Using a validated self-administered modified Rome III questionnaire, functional gastrointestinal disorders including irritable bowel syndrome was assessed. RESULTS: The mean age of study participants was 36.5 years. Irritable bowel syndrome was prevalent among 21.5% of participants. Compared with physically active individuals (≥ 1 hour/wk), those with sedentary physical activity (<1 hour/wk) had 1.27 times greater probability of suffering from IBS (OR: 1.27, 95% CI: 1.08–1.49). However, this association was attenuated after adjusting for age, sex, cigarette smoking and medical history of colitis and diabetes. When the analysis was additionally adjusted for diet-related practices and body mass index (BMI), a non-significant association was found between sedentary physical activity and IBS (OR: 1.18, 95% CI: 0.98–1.41). Gender-stratified analysis revealed similar findings in women either before (OR: 1.29, 95% CI: 1.04–1.61) or after controlling for covariates (OR: 1.27, 95% CI: 0.99–1.62). In BMI-stratified analysis, a significant positive association was seen between sedentary physical activity and IBS among individuals with normal BMI (OR: 1.38, 95% CI: 1.07–1.79). CONCLUSION: We found a significant positive association between sedentary physical activity and IBS, particularly among women and individuals of normal weight.