Metformin versus acarbose therapy in patients with polycystic ovary syndrome (PCOS): a prospective randomised double-blind study.

The objective of this study was to investigate the effect of metformin versus acarbose in terms of ovulation rate, their impact on hormonal and metabolic status and tolerability of both drugs in patients with polycystic ovary syndrome (PCOS). Seventy-five patients with PCOS were included in this prospective randomised controlled double-blinded clinical study. According to randomisation, patients were allocated to receive either metformin 2550 mg/day (n = 37) or acarbose 300 mg/day (n = 38) for 12 weeks. Primary study outcomes were ovulation rate, restoration of a regular menstrual cycle and the incidence of side effects. Secondary outcomes included treatment-related hormonal and metabolic changes. Comparable high rates of regular menstrual cycles as well as ovulation could be achieved in both groups (70% and 73% for metformin vs. 78% and 59% for acarbose, p = 0.330 and p = 0.185, respectively). In contrast, only in patients treated with metformin a statistically significant decrease in fasting insulin and cholesterol levels as well as BMI was observed. However, comparing both groups at the end of treatment, no significant differences in metabolic and/or hormonal parameters could be detected. Regarding side effects, the rate of flatulence and/or diarrhoea was significantly lower for acarbose compared to metformin (38% vs. 80%, p < 0.001).