Both general and central obesity are associated with increased risk of irritable bowel syndrome: a large-scale prospective cohort study.

Abstract

Background: Obesity has emerged as a major public health concern worldwide. However, the relationship between obesity and irritable bowel syndrome (IBS) remains unclear.

Objective: We aimed to systematically examine the association of both general and central obesity measures with risk of incident IBS in a large population-based cohort.

Methods: Participants free of IBS, celiac disease, inflammatory bowel disease and any cancer at baseline were included. Obesity was assessed using various measures of general and central obesity [i.e., Body mass index (BMI), waist circumference (WC), etc]. Primary outcome was incident IBS. Cox proportional hazard model was conducted to estimate the association.

Results: Among 416124 participants (mean age 56.2 years), 133775 (32.1%), 178283(42.8%) and 102139 (24.5%) were BMI-defined normal, overweight and obesity at baseline. During a median of 14.6-year follow-up, 8744 (2.1%) incident IBS were identified. After multiple adjustment, individuals with obesity had a 7% higher risk of developing IBS than those with normal BMI [HR=1.07, (95% CI:1.01,1.13)). As for central obesity, individuals with the highest quartiles of WC [HR=1.14, (95% CI:1.06,1.27)] and visceral adipose tissue (VAT) volume [HR=1.35, (95% CI:1.04,1.75)] had a 14% and 35% greater risk of IBS compared with the lowest quartiles. Similar positive association was observed in other general and central obesity measures, with an 8%-35% higher risk of IBS occurrence in the highest quartile compared with reference group. Further sensitivity analyses and subgroup analyses demonstrated similar results.

Conclusions: Both general and central obesity are associated with increased risk of developing IBS, suggesting the importance of obesity management.