Prevalence of gallbladder polyps among apparently healthy Japanese: ultrasonographic study.

The prevalence of gallbladder polyps was investigated in apparently healthy Japanese who underwent abdominal ultrasonography as part of their health screening examination. The polyps found were differentiated from gallstones, adenomas, or carcinomas as much as possible, and were considered to be cholesterol polyps. The prevalence of such gallbladder polyps was higher among males in every decade of age evaluated. The subjects with gallbladder polyps were more obese than the control group without gallbladder polyps, on abdominal ultrasonograms. The prevalence of gallbladder polyps rose in accordance with a rise in obesity index. At each range of obesity index, the prevalence of gallbladder polyps was higher among males. The prevalence of gallbladder polyps was highest among the middle-aged (40- and 50-yr-old) males, similar to the curve of the obesity index. In females, the obesity index increased with age, with no accompanying rise in the prevalence of gallbladder polyps. These data suggest that obesity contributes to the formation of cholesterol polyps of the gallbladder.