The prevalence of obesity and chronic sleep loss are at record levels among Americans and evidence continues to emerge to support a causal link between the two conditions. Metabolic abnormalities related to sleep disruption are particularly evident in individuals with obstructive sleep apnea (OSA), a disorder traditionally associated with male gender. While more prevalent in men, OSA is underrecognized in women in part because its clinical and polysomnographic features differ from those of men. Women with polycystic ovary syndrome (PCOS) are particularly susceptible to OSA with at least a 5-fold higher risk for its development compared to obese women without PCOS. This study will enroll obese women with PCOS, with and without OSA. Those with OSA will be randomized to receive CPAP or to receive depot leuprolide to suppress ovarian steroid output over 12 weeks, reassessed at 6 weeks, and then randomized (double-blind, placebo controlled) to 6 weeks of either micronized estrogen + placebo or micronized progestin + placebo. The independent effects of androgen, estrogen, and progesterone on OSA and metabolic function will be assessed. In addition, primary human adipocytes will be prepared from fat biopsies obtained from subjects. Insulin sensitivity will be determined by phospho-specific immunoblotting in conjunction with glucose uptake and anti-lipolysis assays. In parallel, adipocytes from these subjects will be cultured for 1-5 days prior to metabolic assays to ascertain if removal of from circulating factors will improve insulin signaling, or if insulin resistance persists in vitro. Finally, there will be an interface with the Metabolomics Laboratory at Duke University (C. Newgard, Lab Director), and metabolomics assessment will be done on blood and urine samples.