 Specific Aim 3: to test the hypothesis that in normal young women, experimental manipulation of sleep that recapitulates the sleep disturbances characteristic of women with PCOS will result in metabolic, hormonal, and cardiovascular alterations that are typical of the metabolic syndrome. A group of healthy young women will be studied twice using a randomized cross-over design. In one study, rapid eye movement REM sleep will be fragmented by experimentally induced microarousals for 3 consecutive nights and non-REM sleep will be left undisturbed. In the other, slow wave activity will be suppressed without awakening the subject and REM sleep will be left undisturbed. Each study will be preceded by 2 nights of baseline sleep. Results were not reported for Aim 3 since no devices or drugs were tested in this aim. 