Obesity boosts risk of diverticulitis and diverticular bleeding
Research Activities, July 2009, No. 347
A diet deficient in fiber is a major risk factor for developing diverticular disease. A new study also implicates obesity in development of the disease. Diverticulitis strikes when pouches (diverticula) form in the wall of the colon and then get inflamed or infected when bacteria get trapped in the pouches. Symptoms include stomach pain, bloating, gas, diarrhea or constipation, nausea, fever, and chills. Lisa L. Strate, M.D., M.P.H., of the University of Washington School of Medicine, and colleagues prospectively studied 47,228 male health professionals (40-75 years old) who were free of diverticular disease in 1986 (baseline). Men reporting newly diagnosed diverticular disease on biennial followup questionnaires were sent supplemental questionnaires. Weight was recorded every 2 years and data on waist and hip circumferences were collected in 1987.
During the 18 years of followup, the researchers documented 801 cases of diverticulitis and 383 cases of diverticular bleeding. After adjustment for other risk factors, men with a body mass index (BMI) of 30 kg/m2 or greater (obese) had a nearly twofold greater relative risk for diverticulitis and more than threefold greater risk for diverticular bleeding compared with men with a BMI of less than 21 kg/m2 (18.5 to 24.9 kg/m2 is normal weight).
Men in the highest quintile of waist circumference compared with those in the lowest quintile had a 56 percent greater relative risk for diverticulitis and nearly twofold increased risk for diverticular bleeding. Similarly, persons in the highest quintile of waist-to-hip ratio had a 62 percent higher risk for diverticulitis and nearly twofold higher risk for diverticular bleeding than those in the lowest quintile. The researchers suggest that obesity may contribute to diverticular disease, because adipose (fatty) tissue secretes a number of cytokines that may precipitate the inflammatory process in the disease. Intestinal microbes that differ between obese and lean individuals may also play a role. The study was supported in part by the Agency for Healthcare Research and Quality (HS14062).
More details are in "Obesity increases the risk of diverticulitis and diverticular bleeding," by Dr. Strate, Yan L. Liu, M.S., Walid H. Aldoori, M.D., M.P.H., Sc.D., and others, in the January 2009 Gastroenterology 136(1), pp. 115-122.