An Assessment of the Effect of HIV and ART on Cardiovascular Risk Factors to Predict Retinal Microvascular Impairment in Pregnant Women: A Pilot Study in a South African Population

Abstract

Background: Human immunodeficiency virus (HIV) and antiretroviral therapy (ART) are known to be involved in cardiovascular disease development. They act alongside systemic risk factors, which interact with both macrovascular and microvascular vessels to accelerate vascular damage. Therefore, the aim of this study was to investigate the cardiovascular risk factors and their relationship with retinal microvascular function in HIV-positive pregnant women on ART in Mthatha, South Africa. Methods: A cross-sectional study was carried out among 78 pregnant women (25 HIV-positive and 53 HIV-negative) in Mthatha, South Africa. Blood pressure (BP) parameters, including systolic BP (SBP), diastolic BP (DBP), and heart rate (HR), were measured, and mean arterial pressure (MAP) was calculated. Lipid profile parameters and fasting blood glucose were assessed. Markers for kidney function, such as albuminuria, were determined. Vascular biomarkers including asymmetric dimethyl arginine (ADMA) and human endothelial specific molecule-1 were quantified. Non-invasive vascular function parameters such as flow-mediated slowing (FMS), carotid-femoral pulse wave velocity (cfPWV), ankle-brachial index, central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), arteriolar venular ratio (AVR), uterine artery pulsatile index (UtA PI) were determined. Results: Diastolic BP, MAP, cfPWV, ADMA, low density lipoprotein (LDL-c) and UtA PI were higher in the HIV-positive group (p <= 0.05) compared to the HIV-negative group. The prevalence of prehypertension/hypertension was higher in the HIV-positive group (p <= 0.05). DBP, MAP, and cfPWV correlated positively with CRVE in the HIV-positive group (p <= 0.05), while AVR negatively correlated with the urinary creatinine (uCr) in the same group (p <= 0.05). Linear regression results demonstrated that DBP, cfPWV, ABI, and LDL-c were predictors of reduced AVR in the HIV-positive group. Conclusions: Increased cardiovascular risk was observed in HIV-positive pregnant women on ART. Further, increased cardiovascular risk such as hypertension and endothelial dysfunction due to ART predicted retinal microvascular dysfunction in the HIV-positive population. This implies a potential mechanistic link between macrovascular dysfunction due to cardiovascular risk factors and retinal microvascular impairment, highlighting the importance of assessing cardiovascular risk early and preserving overall vascular health in HIV-positive population.