The amount of fat carried around the middle, independent of weight, and a high waist-to-hip ratio, increase the likelihood that a woman will have to undergo gallbladder surgery, researchers report. Women with the largest waist circumference have nearly double the risk of women with the smallest waists.

Dr. C-J Tsai and associates at the University of Kentucky Medical Center, Lexington analyzed data for 42,312 participants in the Nurses’ Health Study who ranged in age from 39 to 66 years old and were free of gallstone disease at the start of the study in 1986. Waist and hip circumference data were noted when the women enrolled.

By the year 2000, 3127 of the women had had their gallbladders removed because of gallstones, the investigators report in the medical journal Gut. After adjusting for known risk factors for gallstone disease, women with a waist circumference greater than 36 inches were 96 percent more likely to undergo gallbladder surgery compared with women with a waist circumference less than 26 inches.

“Waist-to-hip ratio was directly associated with risk,” the authors add. A ratio of 0.86 or greater carried a 39 percent higher risk of gallbladder removal than a ratio of 0.70 or less.

Waist-to-hip ratio was a risk factor for gallstone disease and the need for surgery, regardless of overall body mass index.

Ultrasonography screening was not performed in this study, the researchers point out. As a result, the prevalence of gallstones was probably underestimated because most gallstones don’t cause symptoms.

SOURCE: Gut, May 2006.