DALLAS, Dec. 16 – Four hallmarks of the metabolic syndrome – high blood pressure, high blood triglycerides, low blood HDL cholesterol and insulin resistance – are independently and significantly linked to heart attack and stroke, data from a national survey indicates.
The study, reported in today’s rapid access issue of Circulation: Journal of the American Heart Association, is the first to use a large sample of subjects chosen to mirror the U.S. population, researchers said. Many studies have linked the metabolic syndrome to an increased risk of heart attack and/or stroke.
A fifth hallmark of the syndrome is obesity. Having any three of the five conditions amounts to the metabolic syndrome.
The study analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III), a large national survey of the U.S. population ages 20 to 89 taken between 1988 and 1994. The 10,357 subjects were evaluated for the metabolic syndrome and questioned about a history of heart attack or stroke. Twenty-four percent of them had the metabolic syndrome.
The study found that having the metabolic syndrome doubled the risk of heart attack/stroke, said lead author John Ninomiya, a doctoral student in epidemiology at the University of California at San Diego.
High triglycerides had the strongest relationship with disease, increasing the odds of having had a heart attack or stroke by 66 percent. High blood pressure increased the chances by 44 percent. Having insulin resistance – in which the body is unable to process blood sugar efficiently raised the risk by 30 percent. Low HDL cholesterol increased the risk 35 percent.
In this study, abdominal obesity was not independently associated with heart attack or stroke, but other studies have found an association. Obesity contributes to the other syndrome conditions.
In an accompanying editorial, Prakash C. Deedwania, M.D., chief of cardiology at the Veteran’s Administration Central California Health Care System and professor of medicine at the University of California School of Medicine in San Francisco, warns that the increasing rates of metabolic syndrome worldwide could result in a pandemic of cardiovascular disease.
Ninomiya’s co-authors are Michael H. Criqui, M.D., M.P.H.; Gilbert L’Italien, Ph.D.; Joanna L. Whyte, M.S., R.D., M.S.P.H.; Anthony Gamet, Ph.D.; and Roland S. Chen, M.D.