Even for the Overweight, Exercise Helps the Heart
Study finds changes in physical fitness affect disease risk at any weight
TUESDAY, Feb. 7, 2012 (HealthDay News) -- Getting and staying physically fit might help fend off heart disease even if you've put on a few pounds, new research suggests.
"If you would like to reduce the risk of cardiovascular disease, you want to be cautious about weight gain but at the same time concerned about maintaining or improving fitness," said study author Duck-chul Lee, a research fellow at the University of South Carolina, in Columbia.
Maintaining or improving fitness could somewhat counteract the increased risk of fat gain, researchers found. On the other hand, reducing body fat helped make up for the added heart-disease risk linked with losing fitness.
The study is published in the Feb. 14 issue of the Journal of the American College of Cardiology.
Experts have long known that both fatness and fitness affect heart-disease risk factors. However, the researcher say the new study is one of the first to look at how a change in fitness or fatness (or both) affects the development of these risk factors later. The new analysis allowed for fitness and fatness to be adjusted for each other, which isn't taken into account in many studies.
Lee and his colleague followed 3,148 healthy adults enrolled in the Aerobics Center Longitudinal Study. All received at least three extensive medical exams from 1979 to 2006 at the Cooper Clinic, in Dallas.
They looked for any of three risk factors: high blood pressure, high cholesterol or metabolic syndrome.
Metabolic syndrome is a group of signs that raise the risk of diabetes and heart disease. To be diagnosed, someone must have at least three of the five signs: large waist (abdominal obesity), high triglycerides, low "good" cholesterol, high blood pressure and high fasting blood sugar.
Researchers measured fitness with a treadmill test and calculated body fatness with body-mass index (BMI) -- which takes height and weight into account -- and skinfold testing. Researchers looked at changes over time.
At the end of the study, 752 participants had high blood pressure, 426 had metabolic syndrome and 597 had high cholesterol.
Those who maintained or improved fitness over time had a lower risk of developing any of the three risk factors. Those who maintained fitness has a 24 percent lower risk of high blood pressure, 38 percent lower risk of metabolic syndrome and 25 percent lower risk of high cholesterol. Those who gained fitness reduced their risk of each about the same or slightly more.
Those who gained body fat were more apt to develop one of the risk factors than those who lost fat. Gaining fat put the men and women at 24 percent higher risk of getting high blood pressure, 52 percent higher risk of getting metabolic syndrome and 41 percent higher risk of high cholesterol.
Maintaining or improving fitness modified but did not eliminate the increased risk caused by fat gain. And reducing fat seemed to offset part of the higher risk linked with losing fitness.
Best possible scenario? "If you lose fat and gain or maintain fitness, you have the lowest risk of all three risk factors," Lee said.
Being fit and not being fat work independently to reduce risk factors, Lee said. If you can't improve with fitness or fatness? Try to at least maintain, he said.
The study provides some good news, said Dr. Suzanne Steinbaum, director of Women and Heart Disease at Lenox Hill Hospital, in New York City. She is also a spokesperson for the American Heart Association's "Go Red for Women" campaign.
The study, she said, seems to be saying: "If you are fit, it sort of gets rid of some of the risk of being fat. If you are less fat, it gets rid of some of the risks of being less fit than you should be."
She sees this take-home message: "If you are going to be overweight, you have to be fit. Ultimately you have to pay attention if not to both at least to one."
To learn more about metabolic syndrome, go to the American Heart Association.