People living with HIV may lose more years of life through smoking than through HIV, according to a study published in the journal AIDS.
Researchers found smoking and associated lifestyle factors were linked with a two-fold increase in mortality among people living with HIV who had been receiving antiretroviral therapy for at least a year.
The study, which followed about 18,000 people living with HIV in Europe and North America over four years, found that the life expectancy of smokers was on average eight years less than that of nonsmokers, while virally suppressed nonsmokers had a similar life expectancy to nonsmokers in the general population.
Deaths from cardiovascular disease (CVD) and non-AIDS related cancers accounted for most of the excess mortality among smokers. More than one-third of all non-AIDS related cancer deaths were from lung cancer and all deaths from lung cancer were among smokers.
Excess mortality associated with smoking increased markedly with age. However, the study noted cigarettes were unlikely to be the only cause of higher mortality among smokers.
"It is likely that unmeasured confounders, such as alcohol intake and other lifestyle-related factors, contributed to the reduced life expectancy among smokers," researchers explained.
"Such factors are likely to explain the substantially greater rates of liver-related mortality in smokers than nonsmokers."
Notably, the study found that people who quit smoking had similar outcomes to people who never smoked, pointing to the benefits of smoking cessation.
"We were unable to directly assess the impact of smoking cessation on life expectancy, but another study found that the incidence of CVD in HIV patients who stopped smoking during follow-up decreased substantially with increased time since smoking cessation," the study noted.
"This shows the importance of implementing smoking cessation programmes in the HIV-infected population. Training programmes for HIV physicians in smoking cessation counselling may increase rates of smoking cessation among HIV-infected individuals," the researchers advised.
One of the limitations noted by the authors was that there were too few deaths among nonsmoking female participants to provide meaningful estimates of life expectancy and loss of life years. Therefore, study results can only be generalized to the male HIV population.
Katherine Moriarty is a consultant and freelance writer, based in Vancouver. She has 10 years of experience in the intersecting fields of public health and community development, with a focus on bloodborne virus policy and programming.