Impact of Acarbose on Incident Diabetes and Regression to Normoglycemia in People with Coronary Heart Disease and Impaired Glucose Tolerance: Insights from the ACE Trial

OBJECTIVE <p>We examined the impact of acarbose, an alpha-glucosidase inhibitor, on incident diabetes and regression to normoglycemia in 6,522 Acarbose Cardiovascular Evaluation trial participants in China who had impaired glucose tolerance (IGT) and coronary heart disease (CHD).</p> <p>RESEARCH DESIGN AND METHODS</p> <p>Participants were randomly assigned to acarbose or placebo and followed with four-monthly FPGs and annual OGTTs. Incident diabetes was defined as two successive diagnostic FPGs ≥ 7 mmol/L or 2-hr PGs ≥ 11.1 mmol /L while taking study medication, or a masked adjudicated confirmation of this diagnosis. Regression to normoglycemia was defined as FPG <6.1 mmol/L and 2-hr PG <7.8 mmol/L. Intention-to-treat and on-treatment analyses were conducted using Poisson regression models, overall and for subgroups (age, sex, CHD type, HbA_1c, FPG, 2h-PG, BMI eGFR), for IGT alone and for IGT+IFG, and for use of thiazides, ACE inhibitors/angiotensin receptor blockers, beta blockers, calcium channel blockers or statins). </p> <p>RESULTS</p> <p>Incident diabetes was less frequent with acarbose, compared with placebo, being 3.2 and 3.8 <i>per</i> 100 person-years respectively (rate ratio (RR) 0.82, 95%CI 0.71–0.94, p=0.005), with no evidence of differential effects within the predefined subgroups after accounting for multiple testing. Regression to normoglycemia occurred more frequently in those randomized to acarbose, compared with placebo, being 16.3 and 14.1 <i>per</i> 100 person-years respectively (RR 1.16, 95%CI 1.08–1.25, p<0.0001). This effect was greater in participants not taking an ACEi or ARB (RR 1.36, 95%CI 1.21–1.53; P_interaction=0.0006). The likelihood of remaining in normoglycemic regression did not differ between acarbose and placebo groups (P=0.41).</p> <p>CONCLUSIONS</p> <p>Acarbose reduced the incidence of diabetes and promoted regression to normoglycemia in Chinese people with IGT and CHD. </p>