© Nir Elias / Reuters
Marijuana use may be a cause of high blood pressure, a new study reports.

Researchers studied 332 deaths among 1,213 people participating in a larger health study, of whom 57 percent were marijuana users. They had used marijuana for an average of 12 years, and the longer they used it, the more likely they were to have hypertension. The study is in the European Journal of Preventive Cardiology.

After controlling for many health and behavioral variables, including a prior diagnosis of high blood pressure, they found that compared with nonusers, marijuana users had more than three times the risk of death from hypertension-related causes.


Comment: In order to understand whether three times the risk is in fact significant, we need to know what the risk is for non-users. If the risk were say 1 in 1 million, then usage is no big deal. If on the other hand the risk for a non user was 1 in 100 then suddenly three times the risk IS a big deal. By itself though, the description (three times the risk of death) does not actually tell us anything meaningful.


In addition to being a risk for heart disease, hypertension can lead to kidney disease, heart failure and aneurysm. The scientists also noted a link to cardiovascular disease and stroke, both also caused by hypertension, but it was not statistically significant.

The researchers acknowledge the difficulty of measuring frequency and quantities of marijuana use, and the likelihood that illegal use is underreported. The lead author, Barbara A. Yankey, an epidemiologist at Georgia State University, urged caution in interpreting what she called "an exploratory study."

Still, she said, "There is a possibility that marijuana use is related to deaths with hypertension as an underlying cause. People who use marijuana should have regular medical checkups to assess their cardiovascular health."