HIV-infected patients 18 years of age and older with type 2 diabetes or high blood sugar may be eligible for this study. Participants have two clinic visits (1 to 4 weeks apart) at the NIH Clinical Center. At the first visit they provide a detailed medical, social and family history and have blood and urine samples collected. Previous blood sugar values are also recorded. At the second visit, scheduled for 1 to 4 weeks after the first visit, blood and urine samples are collected. Some of the urine and blood samples are stored for future research on diabetes, HIV or related conditions.