Metabolic syndrome in human immunodeficiency virus-positive subjects: prevalence, phenotype, and related alterations in arterial structure and function.

BACKGROUND: Human immunodeficiency virus (HIV) infection itself and highly active antiretroviral treatment (HAART) have been proposed to be associated with a higher prevalence of metabolic syndrome, but, to date, prevalence and phenotype of metabolic syndrome among HIV subjects and the related structural and functional vascular alterations are not conclusively defined. METHODS: We analyzed the data of 108 HIV-infected subjects without known cardiovascular risk factors: 72 were on HAART (group A, age 46.5±7.5 years, clinical blood pressure 125.7/74.9±11.6/7.8 mmHg) and there 36 in a naïve group (group B, age 40.7±7.9 years, blood pressure 126/75.8±9.8/7.7 mmHg). A total of 224 healthy subjects served as controls (group C, age 44.9±6.9 years, blood pressure 123.7/75.7±9.8/7.1 mmHg). Arterial stiffness was measured by aorto-femoral pulse wave velocity (PWV, sfigmocor), and carotid intima media thickness (IMT) was measured by a semiautomatic echotracking system (Esaote-WTS). RESULTS: Metabolic syndrome was more frequent in HIV-positive subjects than in controls (19.4%, 13.8%, 4.5% for groups A, B, and C; P<0.001), with no significant difference between HAART and naïve. In metabolic syndrome subjects, group A displayed lipid profile alterations more frequently (91%, 50%, 57% for groups A, B, and C; P<0.05), whereas others metabolic syndrome components were equally represented in the three groups. In metabolic syndrome subjects, IMT was similar [556±108, 542±164, and 564±110.4 µm for groups A, B, and C; P=not significant (NS)], whereas PWV was significantly greater in HAART subjects when compared with controls (10.8±1.8, 9.±1.1, 9.3±1 cm/sec for groups A, B, and C; P=0.02 for A vs. C). Moreover, in this group (metabolic syndrome+HAART), PWV was higher than in subjects on HAART but without metabolic syndrome. CONCLUSIONS: HIV subjects showed a higher prevalence and a different pattern of metabolic syndrome components. HAART, more than HIV infection per se, appeared to be responsible for the increased prevalence of metabolic syndrome and arterial function derangement.

Clinical applications of arterial stiffness, Task Force III: recommendations for user procedures.

In vivo arterial stiffness is a dynamic property based on vascular function and structure. It is influenced by confounding factors like blood pressure (BP), age, gender, body mass index, heart rate, and treatment. As a consequence, standardization of the measurement conditions is imperative. General and method/device-specific user procedures are discussed. The subject's conditions should be standardized before starting measurements. These conditions include a minimal resting period of 10 min in a quiet room. It also includes prohibitions on smoking, meals, alcohol, and beverages containing caffeine before measurements. The position of the subject and time of measurements should be standardized. In comparative studies, corrections should be made for confounding factors. Repeated measurements are done preferably by the same investigator, and if available validated with user-independent automated procedures. As it is not feasible to discuss all methods or devices measuring arterial stiffness in one article, more attention is given to user procedures of commercially available devices, because these devices are of interest for a wider group of investigators. User procedures of methods/devices are discussed according to the nature of arterial stiffness measured: systemic, regional, or local arterial stiffness. Each section discusses general or method/device-specific user procedures and is followed by recommendations. Each recommendation discussed during the First International Consensus Conference on the Clinical Applications of Arterial Stiffness is quoted with the level of agreement reached during the conference. Also proposals for future research are made.