Sleep-wake Changes of Luteinizing Hormone Frequency in Pubertal Girls With and Without High Testosterone

Inclusion Criteria: * Early to midpubertal girls (late Tanner 1 \[i.e., estradiol \> 20 pg/ml\] to Tanner 3) * Premenarcheal * Approximate ages, 8-15 years Exclusion Criteria: * BMI-for-age \< 5th percentile * Inability to comprehend what will be done during the study or why it will be done * Being a study of GnRH pulse regulation in adolescent girls with and without HA, boys are excluded * Obesity associated with a diagnosed (genetic) syndrome (e.g., Prader-Willi syndrome, leptin deficiency), obesity related to medications (e.g., glucocorticoids), etc. * Pregnancy or lactation * Virilization * Total testosterone \> 150 ng/dl (confirmed on repeat) * DHEAS \> upper limit of age-appropriate normal range (confirmed on repeat) (mild elevations may be seen in adolescent HA, and elevations \< 1.5 times the age-appropriate upper limit of normal will be accepted in such girls) * Follicular phase 17-hydroxyprogesterone \> 250 ng/dl (for girls \< 12 years old) or \> 300 ng/dl (for girls 12 and older) (confirmed on repeat), which suggests the possibility of congenital adrenal hyperplasia. NOTE: If an elevated follicular 17-hydroxyprogesterone is confirmed on repeat testing, an ACTH stimulated 17-hydroxyprogesterone \< 1000 ng/dl will be required for study participation * History of premature adrenarche (i.e., appearance of pubic and/or axillary hair before age 8) * A previous diagnosis of diabetes * Fasting glucose ≥ 126 mg/dl, or a hemoglobin A1c \> 6.5% (confirmed on repeat) * Abnormal TSH (confirmed on repeat) (subjects with adequately treated hypothyroidism, reflected by normal TSH values, will not be excluded) * Abnormal prolactin (confirmed on repeat) (mild elevations may be seen in HA girls, and elevations \< 1.5 times the upper limit of normal will be accepted in this group) * Evidence of Cushing's syndrome by history or physical exam (e.g., history of impaired growth in children, striae) * Hematocrit \< 36% and hemoglobin \< 12 g/dl (confirmed on repeat) * Significant history of cardiac or pulmonary dysfunction (e.g., known or suspected congestive heart failure; asthma requiring intermittent systemic corticosteroids; etc.) * Persistent liver test abnormalities (confirmed on repeat), with the exception that mild bilirubin elevations will be accepted in the setting of known Gilbert's syndrome * Persistently abnormal sodium, potassium, or elevated creatinine concentration (confirmed on repeat) * Bicarbonate concentrations \< 20 or \> 30 (confirmed on repeat) * No medications known to affect the reproductive system, glucose metabolism, lipid metabolism, or blood pressure can be taken in the 3 months prior to the first inpatient GCRC study (or in the 2 months prior to screening) * Such medications include oral contraceptive pills, progestins, metformin, glucocorticoids, psychotropics, and sympathomimetics/stimulants (e.g., methylphenidate) * Patients taking restricted medications will be excluded unless written permission (for the subjects to discontinue the medication) is received from the subject's physician * Weight \< 22 kg is an absolute exclusion criterion (to ensure safe blood withdrawal)