Metformin monotherapy in lean women with polycystic ovary syndrome.

This study was carried out to compare ovulation and pregnancy rates in response to metformin therapy in lean and obese women with polycystic ovary syndrome (PCOS). A total of 34 (17 lean and 17 obese) women with PCOS were treated with 500 mg metformin 3 times daily for 12 weeks. In the lean and obese groups, the mean body mass index was 24 and 36, and the mean fasting insulin concentrations were 12 and 21 mIU/l respectively. There was no difference between the two groups as regarding age, DHEA-S, androstenedione, 17-OH progesterone and LH concentrations. In the lean and obese groups 15/17 women (88%) and 5/17 women (29%) ovulated while 11/17 women (65%) and 3/17 women (18%) conceived respectively. Comparison between the groups was found to be statistically significant. Metformin monotherapy is very effective in improving ovulation and pregnancy rates in lean women with PCOS as compared with obese women.