Pubdate: Mon, 11 Jun 2001 Source: Reuters (Wire) Copyright: 2001 Reuters Limited Details: http://www.mapinc.org/media/364 Author: Will Dunham Bookmark: http://www.mapinc.org/pot.htm (Cannabis) STUDY FINDS USING MARIJUANA UPS HEART ATTACK RISK WASHINGTON (Reuters) - The risk of a heart attack jumps nearly five-fold during the first hour after smoking marijuana, posing a particular threat to middle-aged users of the drug, according to a study released on Monday. Researchers led by Dr. Murray Mittleman, director of cardiovascular epidemiology at Beth Israel Deaconess Medical Center in Boston, interviewed 3,882 people who had suffered a heart attack as part of a study of factors linked to the ailment. The likelihood of suffering a heart attack was 4.8 times greater in the first hour after smoking marijuana when compared to periods of non-use of the drug, Mittleman found. In the second hour after smoking the drug, the risk was 1.7 times greater. Starting in the third hour after smoking marijuana, no significant risk rise was documented. Increasing numbers of people in their 30s, 40s and 50s are marijuana users, as members of the post-World War II baby boom generation who may have started using the drug in the 1960s and 1970s trek through middle age, experts said. Men beginning at about age 45 and women a few years later are at paramount risk of a heart attack. Mittleman said that while the increased risk may be negligible for young marijuana users, it could be deadly for people already at higher risk by virtue of their age or other risk factors. ``I think the message is that for individuals who are entering the age group where coronary disease is prevalent -- particularly if they have established coronary disease or have multiple risk factors -- that they should think about whether it's reasonable to continue smoking marijuana given that it does pose a real health risk to those individuals,'' Mittleman said in an interview. The study appears in the journal Circulation, published by the American Heart Association (news - web sites). More Dangerous Than Sex Smoking marijuana was far less risky as a heart attack trigger than using cocaine, which raises the risk 25-fold during the first hour after use, the study found. The heightened risk from marijuana was roughly equivalent to vigorous exercise for someone of average fitness, and more dangerous than sexual intercourse for a sedentary person. Some 124 patients in the study (116 men and 8 women) reported having smoked marijuana during the year prior to their heart attack. Their average age was about 44, with nearly a quarter of them aged 50 to 69. Nine said they had smoked marijuana within an hour before their heart attack. Marijuana use may trigger a heart attack in one of several ways, said Mittleman, also an assistant professor at Harvard Medical School (news - web sites) and Harvard School of Public Health. He noted that smoking marijuana raises heart rate. ``We know that after smoking a single marijuana cigarette, there is a dose-dependent increase in heart rate, typically a doubling in heart rate is not at all surprising. There are also complicated effects on blood pressure,'' Mittleman added. It may initiate a heart attack by causing a plaque inside a coronary artery to rupture and form a clot, which can block the flow of blood to the heart muscle, the researchers said. Marijuana use is also linked to a rise in the heart's demand for oxygen, while simultaneously lowering the supply of oxygen in the blood. - --- MAP posted-by: Josh Sutcliffe