For those on treatment for HIV, smoking may reduce their life spans more than the virus. With over 40 percent of the U.S. HIV population (some 248,000 individuals) actively addicted to cigarettes, reducing that rate could save a considerable number of cumulative years of life.

“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 Massachusetts General Hospital Division of Pulmonary and Critical Care Medicine, who led the study. “The good news is that quitting smoking can greatly increase life span, and it is never too late to quit.”

Publishing their findings in The Journal of Infectious Diseases, researchers based their estimates on epidemiological data that they fed into a simulation model. They estimated that if people entered HIV care at age 40 and with a CD4 count of 360, those who kept smoking would lose 6.7 years of life to cigarettes if they were men and 6.3 years if they were women, compared with those who never smoked. Those who quit smoking when they entered HIV care would regain 5.7 years of life expectancy if they were men and 4.6 years if they were women.

Factors the researchers found were associated with gaining a greater benefit from quitting smoking when entering HIV care were being younger, having a higher initial CD4 count and remaining completely adherent to an antiretroviral regimen.

If 10 to 25 percent of HIV-positive smokers quit smoking, this would save approximately 106,000 to 265,000 cumulative years of life.

To read the study abstract, click here.

To read a press release about the study, click here.

To read the aidsmap article, click here.