Antiretroviral therapy and risk of high blood pressure

High blood pressure is a known risk factor for heart disease. Blood pressure is measured as two values: a higher value (systolic), which is the maximum pressure reached as the heart beats, and a lower value (diastolic), the lower pressure between heartbeats. Traditionally, medicine has focused on diastolic blood pressure, but both can be risk factors for cardiac and other health problems .

A review of the MACS cohort showed that HIV-positive men not on treatment were significantly less likely to have systolic hypertension than HIV-negative men, and had a similar risk of systolic hypertension to HIV-negative men for the first two years after initiating HAART. However, their risk increased 1.5-fold in comparison to HIV-negative men after more than two years on HAART. Systolic hypertension risk did not increase with the duration of HAART. ¹

A case control study has shown that people with lipodystrophy had significantly higher blood pressure than HIV-positive people without lipodystrophy on HAART. Although there was a trend towards an association between elevated triglyceride levels and hypertension in this study, the only significant relationship was between an increased waist-hip ratio (central fat accumulation) and the development of hypertension. Increased systolic blood pressure was more likely to become elevated in the event of an increased waist-hip ratio. The authors of the study proposed that interventions to manage hypertension should be instituted in patients with three or more elevated systolic blood pressure readings. ²

One retrospective study compared development of high blood pressure among people on indinavir with those on nelfinavir. Twenty-two percent of the indinavir recipients developed high blood pressure compared with 8% of the nelfinavir group. Statistical analysis showed that only indinavir significantly increased a person's risk of hypertension. ³

A study of 2302 HIV-positive individuals in Hawaii observed an increase in average blood pressure over time independent of age, sex and body weight, and significantly higher blood pressure in those receiving HAART. ⁴

Recently, elevated blood pressure has been linked with treatment with ritonavir-boosted lopinavir (Kaletra) in a cohort of 444 patients from the United States. These patients were 2.5 times more likely to have high blood pressure than patients taking efavirenz (Sustiva), although this seemed to be secondary to the drug's effect of increasing body mass index. A similar effect was seen with tenofovir (Viread) and 3TC (lamivudine, Epivir) treatment. The same study also revealed a link between starting antiretroviral therapy at very low CD4 cell counts (below 50 cells/mm³) and high blood pressure. ⁵