Smoking Cessation & Life Expectancy in HIV

Current estimates show that more than 40% of people with HIV in the United States smoke cigarettes, more than double the smoking rate of the general population, and an additional 20% are former smokers. With increasingly effective antiretroviral therapy (ART) continually improving survival among HIV patients in the U.S., these individuals are now regularly living long enough to develop smoking-related conditions—most notably heart disease, COPD, and lung cancer—at high rates. “Among patients who are receiving HIV treatment, smoking is now the leading killer, not the virus itself,” says Krishna P. Reddy, MD.

The Impact of Smoking

For a study published in the Journal of Infectious Diseases, Dr. Reddy and colleagues sought to determine the actual impact of smoking on the life expectancy of people with HIV in the U.S. and what they could potentially gain in life expectancy by quitting smoking. “We used epidemiologic data and a computer simulation model to estimate the average lifespans of Americans living with HIV who are receiving HIV care, based on whether they were current, former, or never smokers,” says Dr. Reddy. “We also accounted for imperfect adherence to HIV drug regimens and lower retention in care in the U.S. In addition, our model accounted for the natural history of HIV responses to treatment. We used our epidemiologic data and the model to estimate the likelihood of death if patients continued smoking as compared with quitting smoking or having never smoked.”

When the study team simulated HIV-infected current smokers with perfect ART adherence and retention in care, they found that life expectancy was 68.6 years for men and 72.1 years for women. “Overall, people with HIV who consistently took ART lost more than 8.0 years of life from smoking, which is about double the loss from HIV itself for such individuals,” Dr. Reddy adds. “Even when we accounted for typical rates of non-adherence to treatment and loss to follow-up from HIV care, we found that smoking still reduced lifespan substantially among people with HIV.”

Cessation Works

The researchers found that life expectancy for men who entered HIV care at age 40, accounting for imperfect medication adherence and loss to follow-up from care, was 65.2 years for current smokers, compared with 70.9 years and 71.9 years for former and never smokers, respectively. For women entering HIV care at age 40, life expectancy was 68.1 years for current smokers, 72.7 years for former smokers, and 74.4 years for never smokers. Men and women who quit smoking upon entering HIV care at age 40 gained 5.7 years and 4.6 years of life expectancy, respectively, when compared with those who did not quit smoking.

“Quitting smoking at a younger age is better, but our research shows that it’s never too late to quit,” says Dr. Reddy (Figure). “Even someone who continues to smoke to age 60 but quits at that age can still improve their life expectancy by more than 2.0 years when compared with someone who continues to smoke. That’s a substantial benefit when you compare it with some of the other treatments that are commonly used in healthcare, not just for people with HIV, but for people who don’t have HIV too. Furthermore, those who entered HIV care with higher CD4 counts appeared to achieve a greater benefit from quitting smoking, most likely because these patients are less likely to die from AIDS.”

Looking Ahead

Smoking cessation is currently not addressed adequately in HIV primary care treatment guidelines, according to Dr. Reddy. “There’s no guidance for HIV care providers on the best ways to help their patients quit smoking,” he says. “Hopefully, our findings can motivate clinicians, HIV care programs, and policy makers to incorporate smoking cessation as a key part of the comprehensive care of patients with HIV.”

Dr. Reddy notes that it would be helpful for future HIV primary care guidelines to address smoking in greater detail and discuss specific smoking cessation therapies to help guide providers. “We also need more studies on smoking cessation interventions, specifically among people with HIV, to determine which approaches optimize smoking cessation rates in this population. There are many strategies to consider, including counseling, medications, and combinations of these approaches.” In the meantime, Dr. Reddy encourages clinicians who treat patients with HIV to inquire about smoking status and provide smoking cessation treatment for current smokers.