Effect of linagliptin compared with glimepiride on postprandial glucose metabolism, islet cell function and vascular function parameters in patients with type 2 diabetes mellitus receiving ongoing metformin treatment

BackgroundThe goal of this study was to investigate the effects of linagliptin compared with glimepiride on alpha and beta cell function and several vascular biomarkers after a standardized test meal. MethodsThirty-nine patients on metformin alone (age, 647years; duration of type 2 diabetes mellitus, 7.84.5years, 27 male, 12 female; HbA(1c), 57.2 +/- 6.9mmol/mol; mean +/- SD) were randomized to receive linagliptin 5mg (n=19) or glimepiride (n=20) for a study duration of 12weeks. Glucagon-like peptide 1, blood glucose, insulin, intact proinsulin, glucagon, plasminogen activator inhibitor-1 (PAI-1), cyclic guanosinmonophosphat and asymetric dimethylarginin levels were measured in the fasting state and postprandial at 30-min intervals for a duration of 5h. The areas under the curve (AUC(0-300min)) were calculated for group comparisons. ResultsHbA(1c), fasting and postprandial glucose levels improved in both groups. An increase in postprandial insulin (22595 +/- 5984pmol/L*min), postprandial intact proinsulin (1359 +/- 658pmol/L*min), postprandial glucagon (317 +/- 1136pg/mL*min) and postprandial PAI-1 levels (863 +/- 467ng/mL*min) could be observed during treatment with glimepiride, whereas treatment with linagliptin was associated with a decrease in postprandial insulin (-8007 +/- 4204pmol/L*min), intact proinsulin (-1771 +/- 426pmol/L*min), postprandial glucagon (-1597 +/- 1831pg/mL*min) and PAI-1 levels (-410 +/- 276ng/mL*min). ConclusionsDespite an improvement in blood glucose control in both groups, linagliptin reduced postprandial insulin, proinsulin, glucagon and PAI-levels. These results indicate an improvement in postprandial alpha and beta cell function, as well as a reduced postprandial vascular risk profile during treatment with linagliptin. Copyright (c) 2014 John Wiley & Sons, Ltd.