EFFECT OF HYPERGLYCEMIA ON GALLBLADDER MOTILITY IN TYPE-1 (INSULIN-DEPENDENT) DIABETES-MELLITUS

Patients with diabetes mellitus are at increased risk of developing gallstones. This has been attributed, among other factors, to alterations in gallbladder motility in the presence of autonomic neuropathy. Since high blood glucose concentrations impair gastric emptying in diabetic patients, we have investigated the effect of acute hyperglycaemia on gallbladder motility. Seven Type 1 (insulin-dependent) diabetic patients were studied twice during euglycaemia (blood glucose 5 mmol/l) and hyperglycaemia (blood glucose 15 mmol/l) using a clamp technique. In addition, seven healthy volunteers were studied during euglycaemia and hyperglycaemia. Gallbladder volumes, measured with ultrasonography, were studied before and during infusion of step-wise increasing doses of cholecystokinin-33, 0.25, 0.5 and 1.0 Ivy Dog Unit kg(-1) h(-1), each dose for 30 min. Mean basal gallbladder volumes were not significantly different in the four experiments. Administration of cholecystokinin resulted in significant (p < 0.05) dose-dependent reductions in gallbladder volume in all experiments. During euglycaemia the gallbladder contraction in diabetic patients was not significantly different from the control subjects. During hyperglycaemia the gallbladder contraction in the diabetic patients was significantly (p < 0.05) reduced compared to euglycaemia only during infusion of 0.25 Ivy Dog Unit kg(-1) h(-1) of cholecystokinin (19+/-6% vs 33+/-6%). Compared to euglycaemia, during hyperglycaemia the gallbladder contraction in the control subjects was significantly (p < 0.05) reduced during infusion of 0.25, 0.5 and 1.0 Ivy Dog Unit.kg(-1).h(-1) of cholecystokinin (14+/-4% vs 31+/-3%; 42+/-6% vs 65+/-5%; 74+/-4% vs 90+/-3%, respectively). It is concluded that during euglycaemia the gallbladder contraction in response to cholecystokinin in Type 1 diabetic patients is not significantly different from control subjects. During hyperglycaemia the gallbladder contraction in response to 0.25 Ivy Dog Unit.kg(-1).h(-1) cholecystokinin, leading to cholecystokinin levels as observed after ingestion of a light meal, is significantly reduced in Type 1 diabetic patients.