The Metabolic Effects of Protease Inhibitors in HIV Infected Children

Inclusion Criteria: * Inclusion criteria for HIV infected children- a) The participants may be either antiretroviral treatment naive, or experienced. Those individuals who are experienced will be treated with at least one new drug in addition to the protease inhibitor. The selection of the new antiretroviral regimen will be directed by a review of the patient's previous drug treatment history and/or the genetic or phenotypic characteristics of the patient's virus; b) We will recruit subjects from all CDC categories. Disease severity will subsequently be analyzed as a covariate; c) There will be no height, weight or other anthropometric inclusion criterion (these factors will be analyzed as covariates); d) All subjects will be studied when they have not had an acute superinfection for at least four weeks. * Inclusion criteria for controls- Control volunteers will be normal healthy children who are matched to the HIV infected population for age, weight and race. Normal health and non-HIV infected status will be determined by history and by medical record review. Ethical considerations preclude HIV testing in normal children. Separate informed consent and assent forms will be utilized for the control and HIV population. Exclusion Criteria: * Exclusion criteria for HIV infected children- Use of Megace@ or another progestational agent, use of anabolic steroids, acute superinfection * Exclusion criteria for controls- Previous medical history of any chronic disease or glucocorticoid use in the last six weeks. Adopted children who have no knowledge of family history.