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Background:  Studies of the association between HAART and elevated blood pressure (BP) have yielded conflicting results.

Methods:  We conducted a case-crossover analysis of data from men enrolled in the Multicenter AIDS Cohort Study who initiated HAART between 1995 and 2003. Only men who had BP measured at 2 points 6 months apart, before and after HAART initiation , and who had never previously taken any anti-hypertension medications were included in this study. Follow-up BP assessments were conducted at 6-month intervals. The primary outcomes were the change in systolic BP and diastolic BP since the last pre-HAART visit. Linear regression models with robust variance estimation to account for correlated data were used to quantify the blood pressure changes over time, and to assess whether the changes were associated with the following characteristics measured prior to HI: age, race, body mass index, and CD4 lymphocyte count.

Results:  The 404 participants included in this study contributed 3637 person-visits to the analysis during the 7-year follow-up period. At the last examination prior to HAART initiation, 35% were younger than age 40 while 15% were 50 or older, 82% were Caucasian, 61% had a body mass index of < 25 kg/m², and 36% had a CD4 count < 200 cells/mL. Overall, initiating HAART was associated with a statistically significant increase in systolic BP (mean increase: 1.8 mm Hg; 95% CI 0.6 to 2.9) while the mean change in diastolic BP of 0.6 mm Hg (95% CI –0.3 to 1.5) was not significant. During follow-up, systolic BP continued to increase significantly by an average of 0.3 mm Hg (95% CI 0.1 to 0.4) every 6 months while diastolic BP remained constant (mean 6-month change = 0.0 mm Hg). In a multiple regression analysis that included age, race, body mass index, and CD4 count, only CD4 count was significantly associated with blood pressure change following HAART initiation. The increase of both systolic BP and diastolic BP immediately following HAART initiation was significantly (p < 0.05) higher among men with CD4 < 200 compared with men with CD4 > 350 (3.6 mm Hg for systolic BP and 2.4 mm Hg for diastolic BP).

Conclusions:  Initiating HAART resulted in increased systolic BP and diastolic BP, primarily among men with more advanced HIV disease prior to HAART initiation. Among all men, each year of HAART use resulted in a 0.6-mm Hg increase in systolic BP while diastolic BP remained constant. The positive correlation between longer HAART exposure and higher systolic BP also suggests that these men may have an increased risk of clinical events related to hypertension.

Keywords: antiretroviral therapy complications; blood pressure; hypertension