Smoking may shorten the lifespan of people living with HIV more than HIV itself
A new study led by researchers at Massachusetts General Hospital (MGH) finds that cigarette smoking substantially reduces the lifespan of people living with HIV in the U.S., potentially even more than HIV itself. The report is being published online in the Journal of Infectious Diseases.
"A person with HIV who consistently takes anti-HIV medicines but smokes is much more likely to die of a smoking-related disease than of HIV," says Krishna Reddy, MD, of the MGH Division of Pulmonary and Critical Care Medicine and the Medical Practice Evaluation Center, who led the study. "The good news is that quitting smoking can greatly increase lifespan, and it is never too late to quit."
While only 15 percent of the general U.S. adult population smokes cigarettes, among people living with HIV the smoking rate is over 40 percent, and an additional 20 percent are former smokers. The widespread use of antiviral medications today allows people with HIV to live longer, but smokers with HIV are developing smoking-related diseases – such as lung cancer, heart disease, and chronic obstructive pulmonary disease (COPD, sometimes referred to as emphysema) – at higher rates than are HIV-uninfected individuals.
The researchers used epidemiologic data to estimate the average lifespans of people living with HIV depending on whether they were current, former or never smokers. Extending a validated simulation model of HIV developed by the team, they demonstrated that a person with HIV could lose more than 8 years of life simply because of his or her smoking habits and unrelated to HIV infection. They also found that, if one-quarter of the people receiving care for HIV in the U.S. who smoke were to quit now, more than a quarter million years of life would be saved.
The study found that for a 40-year-old person who receives care for HIV but – as is often the case in the U.S. – does not perfectly follow recommended treatment, smoking shortens his or her expected lifespan by more than 6 years, compared with a nonsmoker who is similarly not perfectly adherent to antiviral treatment. For someone who adheres well to anti-HIV medicines, smoking shortens his or her expected lifespan by more than 8 years – about double the impact of HIV itself – compared with a nonsmoker who perfectly adheres to treatment. For those who are smokers when they enter treatment for HIV, quitting smoking, particularly at younger ages, was shown to reverse much of the loss of life expectancy.
"Smoking cessation should be a key part of the care of people living with HIV to improve both their lifespan and their quality of life," says study co-author Travis Baggett, MD, MPH, of the MGH Division of General Internal Medicine and the Tobacco Research and Treatment Center.
Rochelle Walensky, MD, MPH of the MGH Division of Infectious Diseases, senior author of the study, says, "It is time to recognize that smoking is now the primary killer of people with HIV who are receiving treatment."
Reddy adds, "Unfortunately, smoking cessation interventions have not been widely incorporated into HIV care. Given how common smoking is among people with HIV, now is the time to change that." Reddy is an instructor in Medicine, Baggett is an assistant professor of Medicine and Walensky is a professor of Medicine at Harvard Medical School.
Additional co-authors of the Journal of Infectious Diseases report are Robert Parker, ScD, Nancy Rigotti, MD, and Kenneth Freedberg, MD, MSc, MGH Division of General Internal Medicine; Elena Losina, PhD, MSc, Brigham and Women's Hospital; David Paltiel, PhD, MBA, Yale School of Public Health; and Milton Weinstein, PhD, Harvard T.H. Chan School of Public Health. The study was funded by National Institutes of Health grants T32 AI007433, R01 AI420006, and R37 AI093269 and the Steve and Deborah Gorlin MGH Research Scholars Award.
Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH Research Institute conducts the largest hospital-based research program in the nation, with an annual research budget of more than $800 million and major research centers in HIV/AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, reproductive biology, systems biology, photomedicine and transplantation biology. The MGH topped the 2015 Nature Index list of health care organizations publishing in leading scientific journals and earned the prestigious 2015 Foster G. McGaw Prize for Excellence in Community Service. In August 2016 the MGH was once again named to the Honor Roll in the U.S. News & World Report list of "America's Best Hospitals."