Acarbose offers superior endothelial function improvement in Type 2 diabetes
MedWire News: The α-glucosidase inhibitor acarbose has a greater beneficial effect on endothelial dysfunction than the insulin-secretagogue nateglinide in patients with newly diagnosed Type 2 diabetes, Japanese scientists have shown.
Outlining the background to their study, Teruo Inoue (Dokkyo Medical University, Tochigi) and associates explain: “The α-glucosidase enzymes metabolize non-absorbable oligosaccharides into absorbable monosaccharides and, thus, acarbose significantly reduces the postprandial rise in glucose without increasing circulating insulin levels.”
Indeed, acarbose has recently been shown to reduce the risk for cardiovascular complications in patients with Type 2 diabetes and individuals with reduced glucose tolerance.
The authors add that, in contrast, “the D-phenylalanine derivative nateglinide is an insulinotropic agent with rapid effects and a short duration of action, which acts as an insulin secretagogue in the treatment of Type 2 diabetes, and which is reported to lower the 24-hour glucose profile without increasing total insulin secretion.”
Previous studies have investigated the effects of acarbose or nateglinide on post-prandial endothelial function; however, the two compounds have not yet been directly compared.
Inoue and team therefore randomly assigned 30 individuals with newly diagnosed Type 2 diabetes to treatment with acarbose 300 mg/day, nateglinide 270 mg/day, or no treatment. The patients were aged an average of 67.8 years and received treatment for 12 weeks. Importantly, before the treatment began, all participants were found to have similar postprandial brachial endothelial function.
As reported in journal Cardiovascular Diabetology, the usual postprandial decrease in endothelial function was significantly blunted in those treated with acarbose compared with those given nateglinide, with reductions in brachial flow-mediated dilation of 1.5% and 3.2%, respectively, compared with 5.0% in those who received no treatment. Specifically, flow-mediated dilation in those given acarbose increased by an average of 6.8% by the end of the study.
Acarbose also significantly improved insulin sensitivity, while nateglinide had no significant effect on insulin response.
Concluding, the authors say that their results at least “partially” support the results of the Study to Prevent Non-Insulin Dependent Diabetes Mellitus (STOP-NIDDM) trial and also a meta-analysis of seven long-term studies demonstrating that acarbose reduces the risk of myocardial infarction in individuals with Type 2 diabetes.
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By Philip Ford