Effect of alpha-glucosidase inhibitors on the progression of carotid intima-media thickness: a meta-analysis of randomized controlled trials.

BACKGROUND: It remains unclear whether lowering postprandial glucose by alpha-glucosidase inhibitors (alpha-GIs) can prevent the progression of carotid intima-media thickness (IMT). METHODS AND RESULTS: We performed a meta-analysis of all relevant randomized controlled trials (RCTs) to evaluate the effect of alpha-GIs on the progression of carotid IMT. Five RCTs with 411 patients were included in this study. Alpha-GIs therapy was associated with a significant reduction in the annual progression of carotid IMT (WMD, -0.06 mm/year, 95% CI -0.11, -0.01; P=0.02) and the progression in carotid IMT at the end of follow-up (WMD, -0.07 mm, 95% CI -0.12, -0.02; P=0.003). In subgroup analysis, alpha-GIs therapy was associated with a significant reduction in the annual progression of carotid IMT in patients with type 2 diabetes mellitus (T2DM) (WMD, -0.08 mm/year, 95% CI -0.10, -0.06; P<0.00001), and in the progression of carotid IMT in patients with impaired glucose tolerance (IGT) at the end of follow-up (WMD, -0.03 mm, 95% CI -0.05, -0.01; P=0.01). Alpha-GIs treatment was associated with significant increase in HDL-C (WMD 1.56 mg/dl, 95% CI 0.09, 3.03; P=0.04) and decrease in basal immunoreactive insulin as well as had favorable trends towards reducing HbA1c, triglyceride and diastolic blood pressure. CONCLUSION: It suggests that alpha-GIs therapy may be an effective strategy in preventing the progression of carotid IMT in patients with IGT or T2DM. It partially contributes to the improvement in atherogenic metabolic parameters induced by alpha-GIs. More studies, especially large multi-centre RCTs, are still warranted to further clarify the anti-atherosclerotic effect of alpha-GIs.