BACKGROUND:
Metabolic syndrome (MetS) is a cluster of risk factors for cardiovascular disease and diabetes, many of which are associated with HIV and antiretroviral therapy (ART). We examined prevalence and incidence of MetS and risk factors for MetS in ART-naive HIV-infected individuals starting ART.

METHODS:
MetS, defined by the Adult Treatment Panel III criteria, was assessed at and after ART initiation in HIV-infected individuals who enrolled in selected AIDS Clinical Trials Group trials and were followed long-term after these trials as part of the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials cohort. Cox proportional hazards models were used to examine risk factors of incident MetS. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CI) are reported.

RESULTS:
At ART initiation, the prevalence of MetS was 20%. After ART initiation, the incidence of MetS was 8.5 per 100 person-years. After adjusting for demographics and body mass index, the risk of MetS was decreased for CD4+ T-cell counts >50 cells per cubic millimeter (aHR = 0.62, 95% CI = 0.43 to 0.90 for CD4 >500), and the risk was increased for HIV-1 RNA >400 copies per milliliter (aHR = 1.55 (95% CI = 1.25 to 1.92) and use of a protease-inhibitor (PI)-based regimen [relative to no PI use, aHR = 1.25 (95% CI = 1.04 to 1.51) for any PI use].

CONCLUSIONS:
In HIV-infected individuals on ART, virologic suppression and maintenance of high CD4+ T-cell counts may be potentially modifiable factors that can reduce the risk of MetS. The effect of MetS on the risk of cardiovascular disease and diabetes needs to be evaluated.