Women with polycystic ovary syndrome (PCOS) often have irregular menstrual periods, too much facial and body hair, and weight gain. Women with PCOS also have a hard time becoming pregnant. Girls with high levels of the male hormone testosterone often develop PCOS as adults. Some girls with high levels of male hormone will develop normal hormone levels as they grow up, but most girls continue to have high levels of male hormone as adults. The purpose of this study is to understand where the male and female hormones come from in girls as they get older. The investigators think the adrenal gland, makes most of the hormones in young girls and that the ovary and the adrenal gland make these hormones in older girls. The investigators would like to find out whether an overactive adrenal gland makes these hormones higher in girls who are overweight, compared to those who are not overweight.

We propose that the adrenal gland is the predominant source of the early morning rise in progesterone and testosterone which is more marked in early puberty. Specifically, we hypothesize that dexamethasone administration at 22:00 will be associated with a dampened progesterone and testosterone rise the subsequent morning in normal girls. We also propose that the adrenal gland is the source of the excess androgen production in young obese girls, and that dexamethasone will decrease their early morning testosterone and progesterone levels. We will explore the hypothesis that functional adrenal hyperandrogenism, or ACTH hyperresponsiveness, is one mechanism underlying this excess adrenal androgen production seen in obesity.

Inclusion Criteria:

• Normal and obese (>95th BMI%) females
• Weight of 24 kg or more
• Early to late puberty (expected age range 7-18)
• Screening labs within age-appropriate normal range, with the exception of a mildly low hematocrit (see below) and the hormonal abnormalities inherent in obesity which could include mildly elevated LH, lipids, testosterone, prolactin, DHEAS, E2, glucose, and insulin; and decreased follicle-stimulating hormone (FSH) and/or sex hormone-binding globulin (SHBG)

Exclusion Criteria:

• Screening labs outside of age-appropriate normal range
• Hemoglobin <12 mg/dL and hematocrit<36% (Subjects will be offered the opportunity to take iron supplementation for 60 days if their hematocrit is slightly low (33-36%) (suggestive of iron deficiency anemia) and will then return for retesting of their hemoglobin/hematocrit. If still <36%, they will be excluded.)
• Morning Cortisol <5 g/dL
• 17-hydroxyprogesterone >295 ng/dL
• Weight<24 kg
• History of Cushing's syndrome or adrenal insufficiency
• Pregnant (self reported)