Reproduction and Metabolism: Insights from Polycystic Ovary Syndrome

Until the 1980s, polycystic ovary syndrome (PCOS) was considered to be a poorly defined reproductive disorder. During that decade, it was recognized that PCOS was associated with profound insulin resistance and a substantially increased risk for type 2 diabetes mellitus in young women. Accordingly, the mechanisms linking the reproductive and metabolic features of the syndrome became the subject of intense investigation. Insulin is now recognized as a reproductive as well as a metabolic hormone and insulin signaling in the central nervous system participates in normal reproductive function. These insights have been directly translated into a novel therapy for PCOS with insulin sensitizing drugs. Androgens also have reversible metabolic actions to decrease insulin sensitivity and increase visceral fat. Prenatal androgen administration to non-human primates, sheep and rodents produces reproductive and metabolic features of PCOS suggesting that the disorder also has developmental origins. PCOS is highly heritable and male as well as female relatives have reproductive and metabolic phenotypes. A number of confirmed genetic susceptibility loci have now been mapped for PCOS and genes in well-known as well as novel biologic pathways have been implicated in disease pathogenesis.