Altered Postprandial Insulin Requirement in IDDM Patients With Gastroparesis

OBJECTIVE To evaluate the effect of gastric emptying on postprandial insulinrequirement in insulin-dependent diabetes mellitus (IDDM) patients with and without gastroparesis. RESEARCH DESIGN AND METHODS Postprandial insulin requirement and gastric emptying were simultaneously evaluated in five IDDM patients with gastroparesis and in six control IDDM patients without gastroparesis. Postprandial insulin requirement after test-meal intake was assessed by measuring the insulin infusion rate during a 4-h feedback control with an artificial endocrine pancreas device (Biostator, Life Science Instruments, Miles, Elkhart, IN). Gastric solid and liquid emptyings were evaluated during the Biostator study by measuring the disappearance rate of 99m Tc in the stomach and in the time course of plasma acetaminophen concentration, respectively. RESULTS Total insulin requirement during the first 120 min after the test-meal intake was significantly lower in the gastroparetic patients than in the control patients. The gastroparetic patients showed no apparent postprandial peak for insulin infusion rate during the 4-h study, although the peak rate was observed within 120 min after the test-meal intake in the control patients. The disappearance of 99m Tc in the stomach was significantly slower, and plasma acetaminophen concentrations were significantlylower in the gastroparetic patients compared with those in the control patients, respectively. CONCLUSIONS The results suggest that IDDM patients with gastroparesis, accompanied by impaired solid and liquid emptying, have an altered postprandial insulin requirement.