Among men who have sex with men (MSM), lung function impairment is more common in those living with HIV.

Researchers analyzed data on 1,067 men from the Multicenter AIDS Cohort Study, which is an ongoing study that enrolls MSM, with and without HIV, at four sites in the United States.

Published in the journal AIDS, the study relied on two measurements of lung function: spirometry and single-breath diffusing capacity for carbon monoxide, known as DLCO.

Spirometry measures the airflow into and out of the lungs. A DLCO result indicates the lung’s capacity to transfer oxygen into the bloodstream.

The men had a median age of 57 years old. Thirty percent were current marijuana smokers, and 24% smoked cigarettes. An additional 45% formerly smoked cigarettes.

On the spirometry test, results were comparable between men with HIV and men without the virus.

The men with HIV had a 2.6% worse DLCO than the HIV-negative men. Having HIV was associated with a threefold greater likelihood of having a DLCO below 60% of the predicted value, indicating severe lung impairment.

Among the HIV-positive men, having a lower DLCO was associated with having had a lower lowest-ever CD4 count.

To read the study abstract, click here.