The impact of cigarette smoking on the life expectancy of individuals who are infected with HIV is even more significant than the disease itself, according to a US-based study reported by Krisha P. Reddy, MD, and colleagues at the Massachusetts General Hospital and Harvard Medical School in the Journal of Infectious Diseases.
“A person who consistently takes HIV medicines but smokes is much more likely to die of a smoking–related disease than of HIV itself,” said Dr Reddy, and the current study was designed to quantify the significance of this effect.
Within the general population, smokers lose about a decade of life, compared to nonsmokers.1 Compared with the general population, people with HIV are more than twice as likely to smoke, as 40% of HIV-infected people are smokers, compared to less than 17% of the general population.2,3
Using a computer simulation and starting at age 40 as a baseline, the investigators projected life expectancy for ART-treated HIV-infected male smokers of 68.6 years and 72.1 years for HIV-infected female smokers. Compared with non-HIV infected smokers of the same age, the additional reduction in life expectancy caused by HIV was 6.7 years for men and 6.3 years for women.
For men who began ART at age 40, the impact of smoking on life expectancy was equal to that of the HIV, while for women, the impact of smoking was greater than the HIV itself.
Impact of Smoking Reduced At Any Age By Quitting
One of the most striking observations of the study was that benefits to quitting smoking were significant at any age; upon entering into HIV care at age 40, men who quit smoking gain 5.7 years of life in addition to that conferred by ART, and women gained 4.6 years, compared to those who did not quit. Quitting at an earlier age than 40 brought even greater gains in life expectancy (close to that of never-smokers), while quitting after age 60 increased life expectancy significantly in men and women by 2.5 years and 2.4 years, respectively.
Next Steps for Improved HIV Survival
The observed impact of ART therapy was exceptionally high at 93% (measured by viral suppression to below detectable levels at 48 weeks). The authors concluded that ART, therefore, has significantly reduced the impact of HIV infection on life expectancy in people consistently adherent to therapy, and the impact of smoking becomes a higher consideration.
“Before the widespread use of antiretroviral therapy, most people with HIV did not survive long enough to experience the consequences of smoking, and thus smoking was not commonly recognized as a threat to their health,” Dr Reddy explained, noting that, “Though the life expectancy of people with HIV has improved, smoking cessation interventions have not been widely integrated into HIV care programs.”
Dr Reddy pointed out that the current study did not directly investigate or address why people with HIV have been less likely to quit smoking than uninfected individuals, which was reported in a previous study by Mdodo et al.4 “Factors associated with smoking, such as depression and alcohol and other substance use, are relatively common among people living with HIV,” Dr Reddy observed, adding that “health care providers might be less likely to discuss smoking cessation with patients living with HIV than they are with other patients.”
- Reddy KP, Parker RA, Losina E, et al. Impact of cigarette smoking and smoking cessation on life expectancy among people with HIV: a US-based modeling study. J Infect Dis. 2016;214:1672-1681. doi: 10.1093/infdis/jiw430
- Trends in current cigarette smoking among high school students and adults, United States, 1965–2014. Centers for Disease Control and Prevention website. http://www.cdc.gov/tobacco/data_statistics/tables/trends/cig_smoking/. Updated March 30, 2016. Accessed December 10, 2016.
- Jamal A, Homa DM, O’Connor E, et al. Current cigarette smoking among adults -United States, 2005–2014. MMWR Morb Mortal Wkly Rep. 2015;64:1233-1240. doi: 10.15585/mmwr.mm6444a2
- Mdodo R, Frazier EL, Dube SR, et al. Cigarette smoking prevalence among adults with HIV compared with the general adult population in the United States: cross-sectional surveys. Ann Intern Med. 2015;162:335-344. doi: 10.7326/M14-0954