Objectives: Diabetes mellitus is one of the risk factors in cholesterol gallstones. Individuals with diabetes mellitus are reported to have a 2-fold to 3-fold increase in the incidence of cholesterol gallstones. Though the pathophysiologic mechanisms of this phenomenon are unclear, hypotheses such as reduced gallbladder motility were presented to explain the higher incidence of gallstones in diabetes.
Methods: We compared the gallbladder volume and ejection fraction of 24 diabetics with those of 19 age-matched and weight-matched controls using real-time ultrasonography. Blood sampling for biochemical study of all the subjects were performed.
Results: No significant differences in any physiochemical parameters between the diabetic group and control group could be found. Fasting gallbladder volume increased significantly in the diabetic group (21.90 +/- 9.53 cm3) compared with the control group (16.99 +/- 5.97 cm3). Gallbladder volume measured after a fatty meal were greater in the diabetic group (10.76 +/- 7.19 cm3) than in the control group (4.22 +/- 3.31 cm3) (p < 0.04). When the diabetic group was divided according to the presence or absence of autonomic neuropathy, a significant reduction of ejection fraction was found in diabetics with autonomic neuropathy (42.75 +/- 19.37%) in comparison with diabetics without autonomic neuropathy (61.75 +/- 17.63%) (p < 0.02).
Conclusions: Gallbladder volume in diabetics was significantly greater compared with that of the control. Moreover, in diabetics with autonomic neuropathy, gallbladder motility was markedly reduced in comparison to diabetics without autonomic neuropathy. Thus, we suggest that impairment of gallbladder motility complicated with autonomic neuropathy causes stasis and results in cholesterol gallstone crystal formation and gallstone growth.