First Author: P.De Boever BELGIUM
Co Author(s): F. Everson T. Nawrot H. Kessler I. Webster N. Goswami H. Strijdom
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HIV-infection and anti-retroviral treatment (ART) are associated with altered cardiovascular risk and changes in vascular structure and function. Fundus imaging is proposed to document microvascular changes. To this end, diameters of retinal vessels, sensitive proxies reflecting hypertension and atherosclerosis, are measured.
Observational longitudinal study in Sub-Saharan Africa
Adult participants are recruited in Cape Town and Worcester (South Africa). Participants are enrolled in the HIV-negative control group, the HIV-positive ART naïve group and the HIV-positive ART group. Baseline examination and a follow-up examination after 18 months are done. The examination consists of a health questionnaire, anthropometric measurements, cardiovascular measurements (flow-mediated dilatation, intima media thickness and retinal analysis), blood and urine chemistry. Here, we report the widths of retinal blood vessels, represented as the central retinal arteriolar/venular equivalent (CRAE/CRVE), and the arteriovenous ratio (AVR).
In December 2016, 134 individuals already enrolled, with 24, 28 and 82 individuals in the HIV-negative control group, the HIV-positive ART naïve group and the HIV-positive ART group, respectively. The average age was approximately 38 years. Population characteristics were not significantly different between the three groups, except for a significantly higher BMI (p<0.05) in the HIV-negative group. Blood pressure was significantly higher in the HIV-negative group (p<0.05). At baseline, CRVE was 236.6±23.9 µm, 249.7±28.5 µm and 231.8±21.8 µm for the HIV-negative control group, the HIV-positive ART naïve group and the HIV-positive ART group, respectively. CRVE was significantly higher in the ART naïve group compared to the ART positive group (p<0.05). CRAE values were not significantly different between the three groups. Linear regression models adjusted for age, gender, BMI, alcohol consumption, smoking and cardiovascular medication showed that HIV-infection was a borderline predictor of AVR (beta coefficient: 0.002; p=0.08) and that ART was a significant predictor of CRVE (beta: -19.6; P = 0.001) and AVR (beta: +0.05; p = 0.015).
Venular diameters were larger in the HIV-positive ART naïve group and this could be due to a higher inflammatory status compared to the ART positive group. The study is ongoing but baseline results show promise of retinal vessel analysis to document microvascular effects in individuals with HIV.