Single-dose acarbose decreased glucose-dependent insulinotropic peptide and glucagon levels in Chinese patients with newly diagnosed type 2 diabetes mellitus after a mixed meal

Background: Acarbose slows down the intestinal absorption of carbohydrates, but its effects on the secretion of incretins are still poorly known. This study aimed to examine the effects of single-dose acarbose on the secretion of incretins in patients with newly diagnosed type 2 diabetes mellitus (T2DM). Methods: In this pilot study, twenty-three patients diagnosed with T2DM were randomly assigned to the oral glucose tolerance test (OGTT) group (n=11) and the mixed meal test (MMT) group (n=12). Fourteen subjects with normal OGTT were included as controls. Plasma glucose, insulin, glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic peptide (GIP) were measured at 0 (fasting), 15, 30, 60, 90, and 120min after nutrient load. A week later, controls underwent MMT, the OGTT group underwent OGTT receiving 100mg acarbose, and the MMT group underwent MMT receiving 100mg acarbose. The same blood markers were measured again. Results: No significant difference was observed in the OGTT group before and after administering acarbose. In the MMT group, postprandial levels of glucose (P<0.01), insulin (P<0.01), glucagon at 15min (P<0.05), glucagon area under the curve (AUC) (P<0.05), GIP levels at 30min (P<0.05), and GIP AUC (P<0.05) were decreased after receiving acarbose with a mixed meal, but GLP-1 levels and GLP-1 AUC did not change. Conclusions: Single-dose acarbose could reduce the secretion of GIP and glucagon after a mixed meal in patients with newly diagnosed T2DM. The influence of acarbose on incretin levels could be related to the types of carbohydrate being consumed. Trial registration: This study was registered with the Chinese Clinical Trial Registry (Registration Number: ChiCTR-TRC-14004260, Date of Registration: 2014-01-19).