Effect of alpha-glucosidase inhibitors on progression of carotid intima-media thickness and incidence of diabetes in patients with impaired glucose tolerance: A meta-analysis

BACKGROUND: Impaired glucose tolerance (IGT) is associated with increased cardiovascular risk. Little is known whether alpha-glucosidase inhibitors (alpha-GIs) can prevent the progression of carotid intima-media thickness (IMT) or the incidence of diabetes, and whether they have any effect on inflammatory biomarkers such as C-reactive protein (CRP) in IGT patients. OBJECTIVE: To perform a systematic review on the effect of acarbose on carotid IMT, incidence of diabetes and CRP in patients with IGT. METHODS AND RESULTS: A meta-analysis of randomized controlled trials (RCTs) comparing acarbose with control group in prediabetes patients was conducted. Eleven RCTs with 2699 patients were included. Alpha-GI therapy was associated with a significant reduction in progression of carotid IMT (weighted mean difference -0.12 mm [95% CI -0.20 mm to -0.04 mm]; P<0.004). It was also associated with decrease in progression of diabetes (OR=0.46 [95% CI 0.33 to 0.65]; P<0.00001) and a significant reduction in serum CRP (weighted mean difference -1.34 mg/L [95% CI -1.91 mg/L to -0.77 mg/L]; P<0.00001). CONCLUSION: The present study suggests that alpha-GI therapy in IGT patients inhibits the progression of diabetes and carotid IMT. The underlying mechanism for preventing carotid IMT progression may be through reducing inflammatory biomarkers such as CRP. More RCTs still need to be carried out to further understand the effect of alpha-GIs on atherosclerosis.