Both general and central obesity are associated with increased risk of irritable bowel syndrome: A large-scale...

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

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.

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 in kg/m²), waist circumference, etc.]. The primary outcome was incident IBS. The Cox proportional hazard model was conducted to estimate the association.

Among 416,124 participants (mean age 56.2 y), 133,775 (32.1%), 178,283 (42.8%) and 102,139 (24.5%) were BMI-defined normal, overweight and obesity at baseline. During a median of 14.6-y follow-up, 8744 (2.1%) incident IBS were identified. After multiple adjustments, individuals with obesity had a 7% higher risk of developing IBS than those with normal BMI [hazard ratio (HR): 1.07; 95% confidence interval (CI): 1.01, 1.13]. As for central obesity, individuals with the highest quartiles of waist circumference (HR: 1.14; 95% CI: 1.06, 1.27) and visceral adipose tissue volume (HR: 1.35; 95% CI: 1.04, 1.75) had a 14% and 35% greater risk of IBS compared with the lowest quartiles. A 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 the reference group. Further sensitivity analyses and subgroup analyses demonstrated similar results.

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