Association Between Human Immunodeficiency Virus (HIV) Infection and Male Hypogonadism

This study is investigating whether HIV infection is associated with low testosterone levels (hypogonadism) in men who have sex with men, compared to HIV-negative men. **You may be eligible if...** - You are a man who has sex with men, either HIV-positive or HIV-negative **You may NOT be eligible if...** - You have used testosterone supplements or anabolic steroids in the past year - You have a history of pituitary, adrenal, or gonad disorders - You have had pituitary surgery or radiation - You have received systemic chemotherapy - You have an active opportunistic infection currently being treated - You have cancer, or severe liver, kidney, or heart disease Talk to your doctor to see if this trial is right for you.