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 (CTN-0049, Project HOPE: Hospital Visit as Opportunity for Prevention and Engagement for HIV-Infected Drug Users). 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. There was a significant smoking-by-time interaction for CD4 cell count, 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.

Conclusion: The results of this exploratory analysis suggest that smoking may play a role in immunologic response in HIV-infected substance users. Future research to replicate this finding and to delineate the potential mechanisms by which smoking may affect HIV progression seems warranted.

Related protocols: CTN-0049