Cortisol Regulation in Polycystic Ovary Syndrome (PCOS)

Inclusion Criteria (Healthy controls): * Healthy * At lifetime maximal weight * Weight stable for at least 6 months prior to study entry * Willing to commit to not making significant changes to their diet or daily activities while enrolled. * Premenopausal * Have regular menstrual cycles * No evidence of hirsutism Additional Inclusion Criteria (Subjects with PCOS): * Clinical findings of amenorrhea or oligomenorrhea dating from menarche * Clinical and/or biochemical evidence of hyperandrogenism * Exclusion of related disorders Exclusion Criteria (Healthy controls): * Less than 18 years of age * Exercise \> 30 minutes/day, 3 times a week * Smokers * Heavy alcohol drinkers (\> 2 drinks/day) * Type 2 diabetes * Medical diagnoses including heart disease and cancer * Psychiatric illness (i.e.depression, psychosis, bipolar, schizophrenia) * Body weight \> 136 kg * Pregnant * Endocrine diseases affecting body composition or androgen levels Additional Exclusion Criteria (Subjects with PCOS): * Laboratory evidence of hyperprolactinemia, thyroid dysfunction, or 21-hydroxylase-deficient nonclassic CAH * Contraindication to pioglitazone (i.e. CHF, impaired liver function, anemia, depressed leukocyte counts, pulmonary disease, known sensitivity to thiazolidinediones.