Does metformin induce ovulation in normoandrogenic anovulatory women?

Objective: This study was undertaken to evaluate the efficacy of metformin in women with anovulation who do not have evidence for hyperandrogenism and classic polycystic ovary syndrome. Study design: A randomized trial of metformin (1500 mg daily) and placebo in 24 anovulatory women was undertaken for 3 months. Assessments of changes in hormone levels and insulin sensitivity were carried out. Abnormal ormonal values were defined by levels exceeding the range in normal ovulatory controls. Results: Anovulatory women had normal androgen levels and luteinizing hormone but had higher serum insulin and lower insulin sensitivity compared with controls. Over 3 months, there were 16 ovulatory cycles with metformin and only 4 with placebo (P<.05). Success of ovulation did not correlate with changes in androgen, insulin, or insulin sensitivity parameters. Conclusion: Metformin may be useful for inducing ovulation in anovulatory women who do not have hyperandrogenism. This effect may be independent of a lowering of androgen or insulin levels