Effect of acarbose on additional insulin therapy in type 2 diabetic patients with late failure of sulphonylurea therapy.

Aim: The present study investigated the effect of acarbose on insulin requirements and glycaemic control in patients with type 2 diabetes receiving exogenous insulin due to secondary failure of maximum dose sulphonylurea therapy.

Methods: A single-centre, double-blind, randomized, placebo-controlled study was performed in 48 type 2 diabetic patients with late-term failure following at least 3 years of sulphonylurea therapy requiring additional insulin therapy to determine the impact of acarbose on glycaemic control and insulin requirements. The primary end points were glycaemic response rate (responders being predefined as patients who achieve a decrease in HbA1c to less than 8% or a reduction by at least 15% as compared to the baseline values) and the daily insulin dose at 6 months. Secondary parameters assessed included postprandial changes in blood glucose, serum insulin and C-peptide during the treatment period.

Results: There were significantly more responders in the acarbose-treated group compared with the placebo group (20/24 patients vs. 10/19 patients; p < 0.05). The mean daily insulin dose after 24 weeks of treatment was 16.4 +/- 10.1 IU in the acarbose group and 22.4 +/- 12.2 IU in the placebo group (mean +/- s.d.; p < 0.07). Postprandial increases in blood glucose, insulin and C-peptide were consistently lower in the acarbose-treated group than in the placebo group. For example, the mean increase in 2-h postprandial serum insulin remained almost unchanged in the acarbose group at the end of 24 weeks of treatment compared to an increase to 43 +/- 29 microU/ml (mean +/- s.d.) at the end of the study period for the placebo group.

Conclusions: The findings of this study suggest that the addition of acarbose to sulphonylurea/insulin combination therapy can improve glycaemic control in type 2 diabetic patients. Acarbose may also reduce insulin resistance and hyperinsulinaemia.