Association between selected immune markers and low ankle-brachial index in virologically suppressed HIV-infected patients on antiretroviral therapy in Nigeria

Abstract

Introduction: People living with human immunodeficiency virus (HIV) on effective antiretroviral treatment (ART) are exposed to an increased risk of cardiovascular disease, often linked to inflammation and immune activation. Ankle-brachial index (ABI) has been widely accepted as screening tool for peripheral arterial disease (PAD) and future cardiovascular events, and is inexpensive and noninvasive compared to carotid intima-media thickness measurements. This study aimed at determining the association between low ankle-brachial index and selected immune markers among virologically suppressed HIV-infected participants on ART in Kwara State, Nigeria. Material and methods: This analytical cross-sectional study was conducted between July 2018 and December 2018. One hundred and fifty HIV-infected participants and fifty HIV non-infected age matched controls were recruited into the study. Ankle-brachial index was measured, and peripheral arterial disease was defined as ABI of < 0.9. Cryopreserved plasma was used to evaluate interleukin (IL)-6 and sCD14. Student’s t-test and c2 test were used to compare continuous and categorical variables. Associations of CVD and immunologic markers with low ABI were assessed using logistic regression analysis. Results: The study group had significantly lower mean values for ABI and significantly higher mean values of IL-6 and sCD14 compared to the control group (p < 0.05). The prevalence of low ABI (14.6%) was higher in the study group compared to the control group (2%). IL-6 (OR 0.992, p = 0.087) and sCD14 (OR 0.918, p = 0.058) were not associated with low ABI in the study group. Conclusions: HIV-infected individuals on suppressive ART demonstrate increased levels of IL-6 and sCD14 compared to not infected controls. The impact of inflammation and immune activation on PAD in treated HIV-infection requires further investigation.