Metabolic Abnormalities - HIV Infected and Uninfected Males

Inclusion Criteria: * Males age 12 years and 0 days through 24 years and 364 days. * Tanner stage 4 or 5. * Accessible medical history and medications history. * Willingness to fast and complete all clinical evaluations and specimen collection. * Willingness and ability to give informed consent or assent with parental/legal guardian permission, where required. Group 1: HIV-Negative Control Subject Specific Inclusion Criteria * All subjects for Group 1 will be tested for HIV-1 to confirm negativity unless they have a documented negative antibody test within the last three months of study entry. * Willingness and ability to give informed consent for HIV testing. Groups 2, 3, and 4: HIV-Positive Subject Specific Inclusion Criteria * HIV-1 infection as documented by a positive result on any of the following licensed tests at any time: any antibody test confirmed by Western blot, HIV culture, plasma HIV-1 RNA PCR \>1,000 copies/ml or HIV-1 DNA PCR. * Horizontal HIV infection transmission (non-perinatal, non-transfusion acquired infection). * Group 2: Currently not on ART and must never have received ART. * Group 3: Currently on a NNRTI, non-PI containing regimen for three or more months, must never have received a total of more than six months of PI-containing regimen and at least one year must have passed since receipt of last PI-containing regimen. * Group 4: Currently on a PI, non-NNRTI containing regimen for three or more months, must never have received a total of more than six months of NNRTI-containing regimen and at least one year must have passed since receipt of last NNRTI-containing regimen. Exclusion Criteria: * Transgender male to female (MTF) or female to male (FTM) youth * Refusal to fast for the 8 hours before collection of laboratory specimen requiring fasting. * Unable to obtain medical/medications history. * History of anorexia or bulimia. * Type I Diabetes Mellitus. * Type II Diabetes Mellitus and cannot omit diabetes medication for the 48-hour period prior to laboratory specimen collection for oral glucose tolerance test (OGTT). * Current use or use within the past 6 months of oxandrolone, nandrolone, oxymetholone, stanozolol, or any other synthetic anabolic/androgenic agents. * Current use or use within the past 6 months of pharmacologic doses of growth hormone. Physiologic growth hormone replacement therapy is permitted, as long as dosages meet the following specifications: * Adolescents in puberty - less than or equal to an equivalent of 0.1 mg/kg/day * Adolescents past puberty - less than or equal to an equivalent of 0.025 mg/kg/day * Current use or use within the past 6 months of pharmacologic doses of testosterone. Physiologic testosterone replacement therapy is permitted as long as dosages meet the following specifications: * Injection - no more than 400 mg/month of testosterone enanthate * Patch - no more than 5 mg/day (e.g. Testoderm, Androderm) * Gel in pre-packaged doses - no more than 7.5 g/day of gel (e.g. Androgel, Testim)