Middle-aged men living with HIV who smoke pot routinely have an increased risk of cardiovascular disease compared with their peers, Reuters Health reports. This association is independent of tobacco smoking.

Living with HIV is associated with an increased risk of cardiovascular disease. Additionally, tobacco smoking in particular can increase the overall risk of death dramatically among HIV-positive individuals.

Publishing their findings in Clinical Infectious Diseases, researchers studied data on 558 HIV-positive men in the Multicenter AIDS Cohort study who enrolled between 1990 and 2010. A total of 376 of them were on antiretrovirals and had a fully suppressed viral load upon entering the study and the remainder tested positive for HIV during the study. The men made twice-yearly visits to the study.

The median age of the participants upon entry into the study was 41. Sixty-six percent were white, and 79 percent had more than a high school education.

The researchers found that 20 percent of the study participants reported heavy marijuana use—defined as smoking daily or weekly—at 50 percent or more of their follow-up visits.

After adjusting the data for age, tobacco smoking, viral load and traditional cardiovascular disease risk factors, the researchers found that heavy pot smoking was associated with a 2.5-fold increased risk of heart disease for men 40 to 60 years old.

The study authors also found that both tobacco and marijuana smoking were independently linked with high white blood cell counts. The men in the top quarter for white blood cell counts among the overall group—specifically, a count of at least 6,500—had a 4.3-fold increased risk of cardiovascular-disease-related health events.

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To read the study, click here.