September 2, 2005
Fitness Trumps Cholesterol as Key to Heart Health
(Kingston, ON) "“ Being physically fit can dramatically reduce men's deaths from heart disease "“ even when their cholesterol rates are high, says Queen's researcher Peter Katzmarzyk.
His new study to be published Tues. Sept. 6 by Circulation: Journal of the American Heart Association shows that, regardless of their cholesterol level, men can cut by half their risk of dying from cardiovascular disease if they are physically fit.
Other Queen's members of the team, from the School of Physical and Health Education, are Chris Ardern and Ian Janssen. Researchers Timothy Church and Steven Blair from the Cooper Institute Centres for Integrated Health Research in Dallas, Texas, are also on the team.
The primary aim of the study was to analyze the effectiveness of last year's modifications to the guidelines from the U.S. National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) for lowering bad (LDL) cholesterol to predict death from cardiovascular diseases.
"We wanted to find out if the new guidelines could identify men at risk for cardiovascular disease," says Dr. Katzmarzyk. "We confirmed that the guidelines do accurately identify men at risk not only of disease, but also at risk of cardiovascular death. We also discovered that fitness is important across the board "“ at every level of cholesterol."
Results also suggest that within a given risk category, physical fitness is associated with a greater than 50-per-cent lower risk of mortality. In this study, physical fitness was four to five, 30-minute segments of activity per week: equivalent to walking 130 to 138 minutes per week.
Researchers analyzed the cardiovascular risk factors and cardio-respiratory fitness of 19,125 men ages 20 to 79, who were treated at a preventive medicine clinic from 1979 -1995, prior to the revised treatment guidelines.
Using the new ATP III classifications:
Ã· 58 per cent of the men would have met the criteria for being "at or below LDL (bad) cholesterol goal";
Ã· 18 per cent would have met the criteria for "therapeutic lifestyle change" "“ meaning diet, physical activity and weight management could lower LDL; and
Ã· 24 per cent would have met the criteria for "drug consideration" for lowering LDL.
There were 179 deaths from cardiovascular disease over more than 10 years of follow-up.
Overall, compared to men who met the acceptable LDL level under the revised guidelines:
Ã· Men who met the criteria for therapeutic lifestyle intervention had twice the risk of cardiovascular disease death; and
Ã· Men eligible for aggressive cholesterol-lowering therapy had almost seven-times the risk.
"Lowering the threshold for consideration of cholesterol-lowering drug therapy for those at high risk will ultimately save lives and also have important implications for the healthcare system," says Dr. Katzmarzyk .
The research was partly funded by the U.S. National Institutes of Health.
On the World Wide Web: