 Specific Aim 2: to test the hypothesis that sleep disturbances cause the hormonal, metabolic and cardiovascular alterations seen in women with PCOS. PCOS women with SDB and matched control women with SDB will be evaluated at baseline and following 8 weeks of CPAP treatment. The primary comparison will be between baseline and post-treatment parameters in PCOS women. The secondary comparison will be the post-treatment change from baseline between PCOS and control women to test the hypothesis that for the same degree in improvement in SDB, the magnitude of change in metabolic and cardiovascular measures will be greater in PCOS than in controls. 