Behavioral: Reduction in behaviors capable of sexually transmitting HIV
Clinic-level risk reduction counseling

Effective antiretroviral therapy has significantly improved and prolonged the lives of HIV-infected persons. However, antiretroviral use has also been associated with a diverse array of "unnatural" metabolic complications and other adverse medical conditions. These problems, together with subsequent longer survival, have increased patients' risk for developing renal, hepatic, cardiovascular, neurological, rheumatologic, and other end-organ diseases, and cancers. Longer survival is also increasing the pool of HIV-infected persons capable of transmitting the virus, which could accelerate the pace of the U.S. epidemic; however, the ability of physicians caring for HIV-infected persons to incorporate prevention into their clinical practices and the effectiveness of this intervention have not been extensively evaluated.

The goals of the Study to Understand the Natural History of HIV and AIDS ("SUN" Study) are:

• to monitor the incidence of metabolic and other medical complications related to the treatment of HIV infection and attendant prolonged survival,
• to identify risk factors associated with the development of these metabolic and other medical complications,
• to monitor the contribution of these complications and other conditions to the morbidity and mortality of HIV infection, and
• to evaluate the efficacy of a structured program of prevention activities, which are integrated into the routine medical care of HIV patients to reduce HIV transmission.

The SUN Study is designed to enroll and follow for 5 or more years a cohort of up to 1,000 HIV-infected adults at HIV specialty care centers in four U.S. cities: Denver, Minneapolis, Providence, and St. Louis. Data will be gathered through longitudinal real-time chart review, biannual physical examination (e.g., body mass index [BMI], blood pressure), repeated non-invasive imaging (e.g., dual energy x-ray absortiometry [DEXA] scanning, carotid ultrasonography) and regularly scheduled laboratory testing (e.g., serum lipids, pap smears, and urinary microalbumin). Data collection and quality control will be managed by Cerner Corporation. After sufficient enrollment, (circa 200 persons per site) a structured prevention program to reduce HIV transmission will be introduced. The impact of this intervention will be evaluated both subjectively (e.g., self-reported change in behavior on an audio computer-assisted self-interviewing [ACASI] questionnaire) and objectively (e.g., change in sexually transmitted disease [STD] incidence).

Outcomes include determination of the incidence of therapy-related metabolic complications and other adverse conditions associated with longer survival, identification of risk factors for these complications and conditions, and reduction in both reported and objective measures of risky sexual behavior.