Strate, L. L. et al. Obesity increases the risk of diverticular bleeding. Gastroenterology 136, 115–122 (2009)

Obesity—specifically central obesity—significantly increases the risk of diverticulitis and diverticular bleeding, according to a new study. “Diverticular disease is extremely common, yet it is difficult to predict which patients will experience complications,” explains Dr Strate, who collaborated on this project with a group from the Harvard School of Public Health.

This team say they are the first to investigate fat distribution and its association with diverticular complications. Strate et al. assessed the relationship between parameters of obesity, diverticulitis and diverticular bleeding over an 18-year period in a large (n = 47,228), prospective study of male health-care professionals who had no diverticular disease at study outset.

BMI ≥30 kg/m2 was linked to increased risk of diverticulitis and diverticular bleeding. “Central obesity (as indicated by waist circumference and waist-to-hip ratio) seems to be particularly important,” says Strate. The investigators found that men in the highest quintile of waist circumference or waist-to-hip ratio had a significantly higher risk of diverticulitis and diverticular bleeding than those in the lowest quintile.

These findings have important public-health implications given the high costs associated with diverticular disease and the lack of measures to prevent its complications. “We intend to confirm our findings in a large cohort of women [and] ... determine what proportion of diverticular complications is attributable to modifiable risk factors such as diet and obesity,” Strate explains.