OBJECTIVE: To evaluate adrenal and ovarian steroidogenesis before and after long-term treatment with metformin in women with polycystic ovary syndrome (PCOS). DESIGN AND METHODS: Twenty-four women with PCOS were evaluated before and after treatment (27+/-4 weeks) with metformin (1000 mg/day) using adrenocorticotrophin (ACTH), GnRH analogue and oral glucose tolerance (oGTT) tests. For statistical evaluation, ANOVA and Wilcoxon's test were used. RESULTS: In 58% of the women a significant improvement in menstrual cyclicity was observed. No significant change in basal steroid levels was found. After ACTH stimulation, a significant decrease in the activity of 3 beta-hydroxysteroid dehydrogenase in C(21) steroids (P<0.05) and in 17 beta-hydroxysteroid dehydrogenase (P<0.01) was observed, as was an increase in the activity of C17,20-lyase in the Delta(4) pathway (P<0.01). A significant growth in the dehydroepiandrosterone (DHEA)/DHEA-sulfate ratio (P<0.05) was detected. With regard to ovarian steroidogenesis, a significant decrease in the stimulated levels of testosterone (P<0.05), index of free testosterone (P<0.01), LH (P<0.05) and oestradiol (P<0.01), and an increase in the levels of 17-hydroxypregnenolone (P<0.05) were detected. In the indices of ovarian enzyme activities, we observed a significant decrease in 3 beta-hydroxysteroid dehydrogenase in C21 steroids (P<0.01), in C17,20-lyase in the Delta 5 pathway (P<0.01), in 17 beta-hydroxysteroid dehydrogenase (P<0.05) and in aromatase. In glucose metabolism, a tendency towards reduction in the homeostasis model assessment (HOMA)-R (for insulin resistance) and HOMA-F (for beta cell function) was detected. In addition, an increase in the levels of C peptide during oGTT was observed (P<0.01). CONCLUSIONS: Long-term metformin treatment reduced various steroid enzymatic activities both in the ovary and the adrenal glands, without apparent changes in basal steroid levels and in insulin sensitivity.
The effects of long-term metformin treatment on adrenal and ovarian steroidogenesis in women with polycystic ovary syndrome