DALLAS, March 24 -- Major changeable risk factors for heart attack include smoking, high blood cholesterol, high blood pressure and physical inactivity. According to a study published in today's Circulation: Journal of the American Heart Association, high blood levels of the fat triglyceride may need to be added to the list.
Researchers in Denmark say that in middle-aged and older white men, a high level of triglycerides -- the chemical form in which most fat exists in food as well as in the body -- may mean a higher risk for heart attack. Therefore, the scientists say, high blood levels of triglycerides should be considered an independent risk factor for heart attack.
In the study, men with the highest levels of triglycerides were more than twice as likely to have a heart attack when compared to those with the lowest triglyceride levels.
An excess amount of triglycerides in blood is called hypertriglyceridemia, which is linked to the occurrence of heart disease in some people. Elevated triglycerides may be a consequence of other diseases, such as diabetes. Like cholesterol, triglyceride levels can be detected with a blood test.
High levels of triglycerides can influence the size, density distribution and composition of LDL (low-density lipoprotein) cholesterol -- the "bad" cholesterol -- leading to smaller, denser LDL particles, which are more likely to promote the obstructions in the blood vessels that trigger heart attack.
"So far our study appears to provide the strongest evidence that higher triglyceride levels are related to increased risk of ischemic heart disease in men independent of other major risk factors such as total cholesterol and HDL (high-density lipoprotein) cholesterol," says Jorgen Jeppesen, M.D., of the Epidemiological Research Unit, Copenhagen University Hospital, Copenhagen, Denmark.