Special Considerations on Hyperandrogenism and Insulin Resistance in Nonobese Polycystic Ovaries Syndrome

Abstract

PCOS is a widespread phenotypically inhomogeneous endocrinopathy with significant health consequences and incompletely elucidated pathogenesis. Though visceral adiposity and insulin resistance (IR) is a well-proved pathogenic set of factors of PCOS, not all women with obesity and IR have PCOS and not all PCOS women are obese and have IR, which is explained by certain genetic backgrounds. The reported prevalence of nonobese PCOS (NonObPCOS) is about 20–30%, but it may be higher because especially in lean women with nonclassical phenotypes PCOS diagnosis is often delayed or unrecognized. Unlike obese PCOS, NonObPCOS management is less clear and is limited to symptomatic treatment. This chapter presents in structured fashion the existing results on the prevalence of NonObPCOS, as well as on special aspects of body composition, IR, and hyperandrogenism pathogenesis, including adrenal contribution in NonObPCOS.