Association between smoking status assessed with plasma-cotinine and inflammatory and endothelial biomarkers in HIV-positive and HIV-negative individuals

Objectives: Smoking is a major contributor to mortality and morbidity in HIV-positive individuals. Our primary objective was to evaluate the association between smoking status determined by plasma cotinine (P-cotinine) concentration and inflammatory and endothelial biomarkers in HIV-positive versus HIV-negative individuals.

Methods: We studied eight inflammatory/endothelial biomarkers [high-sensitivity C-reactive protein (hsCRP), E-selectin, soluble vascular cell adhesion molecule 1 (sVCAM-1), soluble intercellular adhesion molecule 1 (sICAM-1), matrix metallopeptidase 9 (MMP-9), myeloperoxidase (MPO), tissue type plasminogen activator inhibitor 1 (tPAI) and endothelin] in 105 HIV-positive individuals and 105 HIV-negative individuals matched on age, sex and self-reported smoking status. Smoking status was determined using P-cotinine (a concentration > 14 ng/mL was defined as demonstrating exposure to smoke). We used linear regression models to (1) examine the association between smoking status and inflammatory/endothelial biomarkers in HIV-positive compared with HIV-negative individuals, and (2) to determine whether there was evidence to suggest that the impact of smoking status on the biomarkers differed between HIV-positive and HIV-negative individuals.

Results: Of the eight biomarkers, smokers had increased hsCRP, sICAM-1 and MMP-9 concentrations irrespective of HIV status and increasing P-cotinine concentration was associated with increasing hsCRP concentration. We found no interaction between smoking and HIV status. HIV infection was associated with increased hsCRP, E-selectin, sVCAM-1, sICAM-1 and MMP-9 concentrations. Self-reported smoking status differed substantially from smoking status assessed with P-cotinine.

Conclusions: Several biomarkers were associated with smoking status and HIV status. However, our data do not indicate that the effects of smoking on the biomarkers differ between HIV-positive and HIV-negative individuals.