Why are women with polycystic ovary syndrome obese?

INTRODUCTION: Polycystic ovary syndrome (PCOS) is a common condition characterized by reproductive, hyperandrogenic and dysmetabolic features, and often becomes clinically manifest during adolescence, particularly with weight-gain. SOURCES OF DATA: Pubmed search. AREAS OF AGREEMENT: PCOS is heritable and closely associates with obesity (based on data from both epidemiological and genetic studies). Furthermore, insulin resistance forms a central cornerstone of the pathogenesis of PCOS and mediates a close association between obesity and the severity of the phenotypic features of PCOS. AREAS OF CONTROVERSY: Our understanding of the pathogenesis of PCOS remains incomplete, especially regarding its missing heritability (with only a small fraction having been identified from the genome-wide association studies reported to date), and its developmental origins. GROWING POINTS: A challenge for the future is to explore a role for epigenetic modifications in the development of PCOS, and implications for the in utero environment and novel therapeutic opportunities.