OBJECTIVE: Metabolic syndrome (MetS) is directly related to a high incidence of cardiovascular disease in the general population. The association is more doubtful among HIV-infected patients, although MetS has an elevated prevalence in this population. We explored the impact of MetS on early atherosclerosis markers. RESEARCH DESIGN AND METHODS: All HIV-infected outpatients followed at the Brest University Hospital were included in this cross-sectional hospital-based study (SHIVA study, France) (n=154). The MetS status (NCEP ATPIII definition, at least three of these five criteria: fasting glucose, triglycerides, HDL-C, waist circumference and hypertension.) of each patient was analyzed (Mann-Whitney test) according to carotid intima-media thickness, number of plaques, and a combined cardiovascular score. RESULTS: After exclusion of 6 patients treated with statins or insulin or both, MetS status was available for 140 (90.9%) patients and positive for 10 (7.1%). MetS status was due predominantly to blood glucose and triglyceride levels and was strongly correlated with all atherosclerosis markers (p < or = 0.01). CONCLUSION: The MetS prevalence in this population is low for a group with HIV infection, even after inclusion of the statin-treated patients (11.4%), but remains higher than among the general population. MetS in this population is probably a heterogeneous cluster of side effects of antiretroviral therapy (high triglycerides, lower HDL-C, and hypertension) and direct effects of HIV (glucose disturbances). Because it is strongly linked to the presence of plaque and intimal thickness, it is a pertinent criterion for deciding about cardiovascular prevention.