Should insulin-sensitizing drugs be used in the treatment of polycystic ovary syndrome?

Insulin resistance is a central feature of polycystic ovary syndrome (PCOS). Hyperinsulinaemia contributes to anovulation, hyperandrogenism, infertility and early pregnancy loss in women with PCOS. Chronic hyperinsulinaemia also predisposes women with PCOS to increased risks of diabetes and cardiovascular events. Current data indicate that metformin, either as monotherapy or in combination with clomiphene in clomiphene-resistant patients, is an effective treatment for anovulation in PCOS. Initial evidence also suggests that insulin sensitizers may have a role in preventing early pregnancy loss. Of the available insulin-sensitizing agents, metformin has been the agent most frequently studied in PCOS, and has the least undesirable pregnancy safety profile. Ameliorating the metabolic syndrome associated with insulin resistance in PCOS with metformin may also prevent long-term cardiovascular and diabetes complications, pending further evidence. Based on these data, metformin should be a first-line therapy for women with PCOS.