A comparison of acarbose versus metformin as an adjuvant therapy in sulfonylurea-treated NIDDM patients

Abstract

Objective: To compare the effects of acarbose or metformin treatment used as an adjunct with a sulfonylurea agent in the treatment of NIDDM not adequately controlled with the use of a sulfonylurea agent alone.

Research design and methods: Of the poorly controlled female NIDDM patients on sulfonylurea treatment, 18 were randomly selected from the outpatient diabetic clinic for study. For 8 weeks, they received either acarbose (300 mg/daily) or metformin (1,500 mg/daily) in addition to sulfonylurea in a crossover design using a 3-week washout period between treatments. The efficacy of each drug regimen was assessed by measuring the levels of glycosylated hemoglobin, fasting and 2-h postprandial blood glucose (PPBG) levels, cholesterol, triglyceride, and fibrinogen levels before and after 8 weeks of therapy.

Results: The metabolic parameters measured before initiation of either treatment regimen were similar. Mean fasting and 2-h postprandial glucose levels were reduced moderately at the end of 8 weeks of both combination treatments (P < 0.05). Although the fasting and 2-h postprandial plasma insulin and C-peptide and fibrinogen levels at the end of the 8-week treatment periods were lower than those obtained at the beginning of the study, the differences between these values were not statistically significant. Cholesterol levels remained unchanged. Only the 2-h PPBG level in the group using acarbose plus a sulfonylurea was lower than the level achieved by the group using metformin plus a sulfonylurea (8.1 +/- 0.8 vs. 9.8 +/- 1.0 mmol/l, respectively, P < 0.05). The difference between pre- and posttreatment levels of the 2-h PPBG level in both arms of the study were statistically significant (delta-acarbose, 5.3 +/- 0.4 vs. delta-metformin, 2.9 +/- 0.3) (P < 0.05). Specific drug-associated side effects were observed in 12 patients on acarbose and 3 patients on metformin.

Conclusions: Acarbose or metformin can be used as effective adjuvant therapies with a sulfonylurea agent in NIDDM patients who are poorly controlled with the sulfonylurea agent alone.