Author: Mark Mascolini
29 July 2010
A lower nadir (lowest-ever) CD4 count independently correlated with arterial stiffness in a cross-sectional study of US men with HIV. The two noninvasive measures of arterial stiffness used in this San Francisco study are both sensitive measures of cardiovascular risk.
HIV-positive survivors have an above-average risk of cardiovascular disease. To better define associations between HIV disease, traditional cardiovascular risk factors, and cardiovascular risk, researchers at the University of California, San Francisco measured arterial stiffness by pulse wave analysis and carotid-femoral pulse wave velocity in 80 HIV-positive men, all of whom had an undetectable viral load.
In univariate statistical analyses (weighing the impact of one risk factor at a time), age, blood pressure, antihypertensive medication use, and nadir CD4 count below 350 cells/μL predicted worse arterial stiffness (all P < 0.05).
Multivariate analysis considered HIV-related risk factors and traditional cardiovascular risk factors: age, blood pressure, antihypertensive medication use, diabetes, hypercholesterolemia, and smoking. In this analysis, a nadir CD4 count below 350 cells/μL was independently associated with a 0.41 m/sec increase in pulse wave velocity (95% confidence interval 0.03 to 0.79, P = 0.03) and a 7.3% increase in augmentation index (augmentation index normalized for heart rate of 75 beats/min; 95% confidence interval 2.6 to 11.9, P = 0.003).
In the multivariate analysis, neither duration of antiretroviral therapy nor protease inhibitor use correlated with arterial stiffness.
The investigators believe their findings “suggest that cardiovascular risk among HIV-infected individuals could be reduced through early initiation of antiretroviral therapy, before CD4+ T-cell counts are depressed, a concept that should be tested prospectively in future studies.”
Source: Jennifer E. Ho, Steven G. Deeks, Frederick M. Hecht, Yu Xie, Amanda Schnell, Jeffrey N. Martin, Peter Ganz, Priscilla Y. Hsue. Initiation of antiretroviral therapy at higher nadir CD4+ T-cell counts is associated with reduced arterial stiffness in HIV-infected individuals. AIDS. 2010; 24: 1897-1905.
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