Marijuana use may up death risk of from hypertension

Marijuana use may increase the risk of death from hypertension by three times, a study has warned.

"Steps are being taken towards legalisation and decriminalisation of marijuana in the US, and rates of recreational marijuana use may increase substantially as a result," said Barbara A Yankey, a PhD student at the Georgia State University in the US.

"However, there is little research on the impact of marijuana use on cardiovascular and cerebrovascular mortality," said Yankey, lead author of the study published in the European Journal of Preventive Cardiology.

Researchers took data from the US National Health and Nutrition Examination Survey (NHANES) of participants aged 20 years and above. In 2005-2006, participants were asked if they had ever used marijuana.
 

Those who answered "yes" were considered marijuana users. Participants reported the age when they first tried marijuana and this was subtracted from their current age to calculate the duration of use.

Information on marijuana use was merged with mortality data in 2011 from the US National Centre for Health Statistics.

The researchers estimated the associations of marijuana use, and duration of use, with death from hypertension, heart disease, and cerebrovascular disease, controlling for cigarette use and demographic variables including sex, age, and ethnicity.

Death from hypertension included multiple causes such as primary hypertension and hypertensive renal disease.

Among a total of 1,213 participants, 34 per cent used neither marijuana nor cigarettes, 21 per cent used only marijuana, 20 per cent used marijuana and smoked cigarettes, 16 per cent used marijuana and were past-smokers, five per cent were past-smokers and 4% only smoked cigarettes. The average duration of marijuana use was 11.5 years.

Marijuana users had a higher risk of dying from hypertension. Compared to non-users, marijuana users had a 3.42-times higher risk of death from hypertension and a 1.04 greater risk for each year of use.

There was no association between marijuana use and death from heart disease or cerebrovascular disease.

"We found that marijuana users had a greater than three- fold risk of death from hypertension and the risk increased with each additional year of use," Yankey said.