HIV infection and hypertension: Epidemiological and pathogenetic aspects

Abstract

After introduction of antiretroviral therapy (ART), an increased risk of cardiovascular disease (CVD) and other non-AIDS related diseases has been observed HIV-infected individuals. Hypertension is a major risk factor for CVD. Chronic immune dysfunction has been proposed as a driving force of CVD in HIV-infection, and microbial translocation, i.e. the translocation of bacterial products from the gut into the systemic circulation, is a contributor to chronic immune dysfunction in HIV. The overall aims of the thesis were to describe hypertension in HIV-infected patients, and to explore putative HIV-specific risk factors for hypertension.<br><br> In a longitudinal study, blood pressure levels were followed in 434 HIV-infected individuals over a period of 3.5 years. Nadir CD4 cell count was recorded as the lowest CD4 cell count ever for each individual. Around 10% of the persons developed new-onset hypertension, and increased HIV duration was an independent predictor of new-onset hypertension. Close to one third (28%) of the study population were hypertensive throughout the study period. Advanced immunodeficiency, i.e. nadir CD4 < 50 cells/µL, as well as the duration of ART were independent predictors of sustained hypertension in addition to classical risk factors. In an exploratory study which included 42 HIV-infected individuals, microbial translocation was quantified by levels of lipopolysaccharide (LPS). LPS was measured in blood samples collected at the time of nadir CD4 count, and all participants were ART-naïve at nadir. LPS was inversely correlated with nadir CD4 cell count. LPS adjusted for age and gender was a predictor of later blood pressure level and hypertension. <br><br> In conclusion, HIV-related factors such as advanced immunodeficiency, duration of ART and microbial translocation may contribute to the development of hypertension in HIV-infected individuals. Microbial translocation may in fact explain the association between previous immunodeficiency and hypertension.