Heart rate variability, HIV and the risk of cardiovascular diseases in rural South Africa

Background. Antiretroviral therapy transformed human immunodeficiency virus (HIV) infection into a chronic disease. Possible HIV-associated complications have emerged including cardiovascular diseases (CVD). Aim: This study aims to determine the distribution of heart rate variability (HRV) and the association between HRV and HIV in a rural African population. Methods. This cross-sectional study included participants of the Ndlovu Cohort Study, South Africa. HRV was measured using a standardized 5-minute resting ECG and assessed the standard deviation of the normal RR intervals (SDNN), the root of the mean squares of successive RR differences (RMSSD), the percentage of RR intervals greater than fifty milliseconds different from its predecessor (pNN50), total-, low- and high-frequency power. CVD risk factors were assessed using measurements (blood pressure, anthropometry) and questionnaires (e.g. socio-demographics, alcohol, smoking, physical activity). We used a Wilcoxon rank test to assess the difference in medians between HIV-infected and HIV-uninfected participants and multivariable linear regression to investigate the association between HRV and HIV. Results. The study included 325 participants, of whom 202 (62.2%) were HIV-infected. HIV-infected participants drank less alcohol, were more physically active and had lower educational attainment and systolic blood pressure. The medians of all HRV parameters were lower for the HIV-infected compared to HIV-uninfected participants. A significant inverse association was found between HIV and SDNN, RMSSD and pNN50. In addition, age was found to be associated with a decrease of all HRV parameters. Conclusion. Although HIV-infected participants presented with less CVD risk factors they had a lower HRV, indicating an increased risk of CVD and underlining the importance of embedding CVD prevention in HIV-care.