Obesity ups risk of irritable bowel syndrome

General and central obesity are both significant risk factors for the development of irritable bowel syndrome (IBS), suggests a study.

A total of 416,124 participants (mean age 56.2 years) were included in the analysis. Of these, 133,775 (32.1 percent) were BMI-defined normal, 178,283 (42.8 percent) were overweight, and 102,139 (24.5 percent) had obesity at baseline.

Incident IBS developed in 8,722 (2.1 percent) individuals over a median follow-up of 14.6 years. Those with obesity showed a 7-percent increased risk of IBS compared with participants with normal BMI (hazard ratio [HR], 1.07, 95 percent confidence interval [CI], 1.01–1.13) after multiple adjustments.

Among individuals with central obesity, IBS risk was greater in the highest quartiles of waist circumference (HR, 1.14, 95 percent CI, 1.06–1.27) and visceral adipose tissue volume (HR, 1.35, 95 percent CI, 1.04–1.75) compared with the lowest quartiles.

This positive association persisted in other general and central obesity measures, with an increased IBS risk ranging from 8 percent to 35 percent in the highest quartile compared with the reference group. Further sensitivity and subgroup analyses generated comparable results.

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

This prospective cohort study included individuals free of IBS, coeliac disease, inflammatory bowel disease, and any cancer at baseline. The investigators assessed obesity using various measures of general and central obesity, such as BMI and waist circumference.

Incident IBS served as the primary endpoint. The associations were examined using a Cox proportional hazard model.