Cigarette smoking is associated with a significantly elevated rate of cardiovascular disease among people with HIV, but the risk begins to drop after quitting and continues to decline over time, according to findings from the large D:A:D (Data Collection on Adverse events of Anti-HIV Drugs) study presented at CROI (abstract 124).

D:A:D includes more than 33,000 HIV positive participants in the U.S., Europe, and Australia with generally well-controlled HIV disease (most on ART, more than 60% with viral load below 50 copies/mL, median CD4 count about 450 cells/mm³). More than one-third were current smokers and 19% were former smokers; about 8,200 said they quit after entering the cohort.

Current smokers had more than three times the risk for myocardial infarction (MI; heart attack) and ex-smokers approached twice the risk compared with people who never smoked. Among people who quit smoking during follow-up, excess MI risk decreased from 3.73-fold higher during the first non-smoking year, to 3.00-fold after 1-2 years, and finally to 2.07-fold after more than three years -- still about twice the risk of life-long nonsmokers.

Looking at a broader endpoint of cardiovascular disease, current smokers had 2.19-fold higher risk and former smokers had a 1.38-fold higher risk relative to nonsmokers. Again, excess risk declined steadily among people who quit during the study, falling from 2.32-fold higher during the first year to 1.49-fold after more than three years. But the risk of mortality due to all causes did not decrease in a similar pattern, suggesting that risk of death remains elevated after quitting. "Smoking cessation efforts should be a priority in the management of HIV-positive patients," the researchers recommended.

Liz Highleyman (liz@black-rose.com) is a freelance medical writer based in San Francisco.