Baseline Cigarette Smoking Status as a Predictor of Virologic Suppression and CD4 Cell Count During One-Year Follow-Up in Substance Users with Uncontrolled HIV Infection

Cigarette smoking is prevalent in people living with HIV/AIDS (PLHIV) who abuse alcohol and/or illicit substances. This study evaluated whether smoking is predictive of virologic non-suppression (> 200 copies/mL) and low CD4 count (< 200 cells/mm³) during 1-year follow-up in medically hospitalized, substance-using PLHIV recruited for a multi-site trial. Smoking status was assessed with the Heaviness of Smoking Index (HSI). Analyses revealed that, controlling for baseline differences and adherence to antiretroviral therapy, non-smokers (n = 237), compared to smokers scoring in the medium-to-high range on the HSI (n = 386), were significantly more likely to achieve viral suppression (OR 1.50, 95% CI 1.02, 2.20). There was a significant smoking-by-time interaction for CD4 cell count (χ²(1) = 4.08, p < .05), with smokers less likely to have low CD4 count at baseline and 6-month follow-up, but more likely to have low CD4 count at 12-month follow-up. The results suggest that smoking may play a role in immunological functioning in HIV-infected substance users. ClinicalTrials.gov Identifier: NCT01612169.