THE EFFECT OF ACARBOSE ON INSULIN SENSITIVITY IN SUBJECTS WITH IMPAIRED GLUCOSE-TOLERANCE

OBJECTIVE - To study the effect of acarbose, an alpha-glucosidase inhi bitor, on postprandial plasma glucose and insulin and insulin sensitiv ity in subjects with impaired glucose tolerance (IGT). RESEARCH DESIGN AND METHODS - Subjects with IGT were randomly treated in a double-bli nd fashion with placebo (n = 10) or acarbose (n = 8) at 100 mg t.i.d. for 4 months. All subjects were submitted before randomization and at the end of the study to a standardized breakfast and a 12-h daytime pl asma glucose and plasma insulin profile, and insulin sensitivity was m easured as steady-state plasma glucose (SSPG) using the insulin suppre ssion test. RESULTS-While placebo had no effect on postprandial plasma glucose and plasma insulin incremental area under the curve (AUG) (3. 03 +/- 0.5 vs. 3.76 +/- 0.6 mmol . h(-1) . l(-1), P = NS; 1,488 +/- 22 9 vs. 1,609 +/- 253 pmol . h(-1) . l(-1), P = NS), acarbose resulted i n a significant reduction for both glucose (1.44 +/- 0.3 vs. 4.45 +/- 0.9 mmol . h(-1) . l(-1), P = 0.002) and insulin (626.7 +/- 104.3 vs. 1,338.3 +/- 220.5 pmol . h(-1) . l(-1), P = 0.003). The reduction in 1 2-h plasma glucose and insulin AUC on acarbose (11.2 +/- 2.1 mmol . h( -1) . l(-1) and 7.5 +/- 0.7 nmol . h(-1) . l(-1)) was significantly gr eater than that on placebo (4.0 +/- 1.6 mmol . h(-1) . l(-1) and 0.8 /- 0.4 nmol . h(-1) . l(-1)) (P = 0.014 and 0.041). While SSPG was not affected by placebo (13.9 +/- 0.4 vs. 13.8 +/- 0.3 mmol/l; P = NS), i t was significantly improved by acarbose (10.9 +/- 1.4 vs. 13.1 +/- 1. 5 mmol/l, P < 0.004) and was also significantly different from placebo at 4 months (P < 0.02). CONCLUSIONS - It is concluded that in subject s with IGT, acarbose treatment decreases postprandial plasma glucose a nd insulin and improves insulin sensitivity. Acarbose may therefore be potentially useful to prevent the progression of IGT to NIDDM.