Acarbose slows progression of intima-media thickness of the carotid arteries in subjects with impaired glucose tolerance

Background and Purpose - Impaired glucose tolerance (IGT)-a prediabetic state - is an important risk factor for atherosclerosis. Acarbose, an alpha-glucosidase inhibitor, was shown in the placebo-controlled prospective study to prevent noninsulin-dependent diabetes mellitus (STOP-NIDDM) trial to reduce the risk of diabetes by 36% in IGT subjects. This article reports on a placebo-controlled subgroup analysis of the STOP-NIDDM study to examine the efficacy of acarbose to slow progression of intima-media thickness (IMT) in subjects with IGT. Methods - One hundred thirty-two IGT subjects were randomized to placebo (n = 66) or acarbose (n = 66) 100 mg 3 times daily; the study duration was at least 3 years, mean follow-up time 3.9 (SD 0.6) years. Carotid IMT was determined at study entry and the end of the trial. The intent-to-treat analysis included 56 subjects in the acarbose and 59 in the control group who had a baseline and endpoint measurement. Results - A significant reduction of the progression of IMTmean was observed in the acarbose group versus placebo. After an average time of 3.9 years, IMTmean increased by 0.02 (0.07) mm in the acarbose group versus 0.05 (0.06) mm in the placebo group (P = 0.027). The annual increase of IMTmean was reduced by approximate to50% in the acarbose group versus placebo. Multiple linear regression revealed IMT progression as significantly related to acarbose intake. Conclusions - Acarbose slows progression of IMT in IGT subjects, a high-risk population for diabetes and atherosclerosis. This is the first placebo-controlled prospective subgroup analysis, demonstrating that counterbalancing of postprandial hyperglycemia may be vasoprotective.