A study was undertaken to compare the prevalence of gallstone disease (gallstones observed on ultrasound or history of cholecystectomy) in 308 diabetics and 318 controls. There was a higher prevalence of gallstone disease (GSD) in diabetics (32.7%) compared to controls (20.8%; P < 0.001 chi-squared test). However, when gender was taken into account, the difference was only significant in females (diabetics 41.8% versus controls 23.1%; P < 0.001). Analysis by type of diabetes revealed that subjects with non-insulin-dependent diabetes mellitus (NIDDM) had a higher prevalence of GSD than controls for both genders: males-controls 18.1%, NIDDM 33.3% (P < 0.05), IDDM 15.6% ns; females-controls 23.1%, NIDDM 48.6% (P < 0.001), IDDM 36.3% (P < 0.05). On univariate analysis the following risk factors were associated with gallstones (P < 0.1): increased age, body mass index (BMI), triglycerides, LDL cholesterol, decreased HDL cholesterol, alcohol intake, family history of GSD, and female parity > 3. Using stepwise multiple, logistic regression, the following variables were identified as independently predictive of gallstones for each gender/diabetic combination: Males-NIDDM (N = 54), increased age, and decreased HDL; IDDM (N = 90), age and family history; Females-NIDDM (N = 74), increased age, diabetes, increased BMI, and decreased alcohol; IDDM (N = 91), increased BMI, age, decreased alcohol and family history. The proportion of subjects who underwent cholecystectomy was higher in females (46.7%) compared to males (21.7%; P < 0.01) but there were no differences between diabetics and controls in either sex. In conclusion, there was a higher prevalence of GSD in diabetics compared to controls. However, GSD is multifactorial and only in NIDDM females was diabetes an independent risk factor. The proportion of diabetics and controls with GSD who underwent cholecystectomy was equivalent.

The aim of this study was to describe the natural history of gallbladder polyps. Thirty-eight subjects who had been previously identified as having gallbladder polyps in an epidemiologic study of gallstone prevalence in 627 diabetic subjects and matched controls were followed longitudinally. Follow-up sonograms were obtained on 33 and 22 of the 38 subjects at 2 and 5 years, respectively. Prevalence for gallbladder polyps in this population was 6.7%, with a marked male predominance (odds ratio 2.3). No statistical difference in prevalence was found between diabetic subjects and nondiabetic controls. Ninety percent of the polyps were less than 10 mm in diameter, with no polyp being larger than 12 mm. During the follow-up period no changes suggestive of malignant transformation were observed. In conclusion, we found that gallbladder polyps were relatively common and that few significant changes occurred over a 5 year period. In asymptomatic subjects in whom gallbladder polyps less than 10 mm in diameter are found incidentally, the likelihood of malignant transformation is low.