New York, Aug 9 (IANS) Marijuana use is associated with a three-fold risk of death from hypertension, warns new research. "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," said lead study author Barbara Yankey, a PhD student in the School of Public Health, Georgia State University, Atlanta, US. The researchers designed a retrospective follow-up study of the US National Health and Nutrition Examination Survey 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 National Centre for Health Statistics. Among a total of 1,213 participants, marijuana users had a higher risk of dying from hypertension, according to the findings published in the European Journal of Preventive Cardiology. Compared to non-users, marijuana users had a 3.42 times higher risk of death from hypertension. "Our results suggest a possible risk of hypertension mortality from marijuana use. This is not surprising since marijuana is known to have a number of effects on the cardiovascular system," Yankey said. Marijuana stimulates the sympathetic nervous system, leading to increases in heart rate, blood pressure and oxygen demand. Emergency rooms have reported cases of angina and heart attacks after marijuana use," Yankey pointed out. The cardiovascular risk associated with marijuana use may be greater than the cardiovascular risk already established for cigarette smoking, the researchers said. "We found higher estimated cardiovascular risks associated with marijuana use than cigarette smoking," Yankey added.