News Release

The Skinny On Fast Fat: Slow Down Weight Gain To Lower Blood Cholesterol

Peer-Reviewed Publication

American Heart Association

DALLAS, Nov. 13 -- Middle-age may not only be accompanied by higher numbers on the scales, but also higher blood levels of cholesterol, according to a study in this month's Arteriosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association.

In a 20-year study, Ohio researchers examined the relationship between weight gain -- particularly in the amount of body fat -- and total cholesterol and low-density lipoprotein (LDL), the "bad" cholesterol that helps create the obstructions that trigger a heart attack or stroke.

The researchers found that men and women who put on more fat tended to have higher blood levels of LDL and lower blood levels of high-density lipoprotein (HDL), the "good" cholesterol.

"As we get older, we need to be concerned about how much body fat we are putting on. The faster the increase in body fat, the worse the cholesterol profile becomes," says the study's lead author, Roger Siervogel, Ph.D., Fels professor, division of human biology, Wright State University School of Medicine, Yellow Springs, Ohio.

"Even small changes in fatness affect a person's heart disease and stroke risk," he says. "The more fat we put on, the worse lipid profile we have, especially as we approach middle age. The take-home message is don't get fat, eat right and exercise more."

Researchers followed 202 men and 221 women for up to 20 years in the Fels Longitudinal Study. Participants were examined every two to five years to determine their blood cholesterol levels, total body fat, fat-free mass and total weight. Total weight was determined on a regular scale, and total body fat calculated by weighing people underwater. Underwater weight and weight on land were used to determine fat-free mass. Body mass index, a measure of fatness, also was calculated. Males and females were divided into two age groups: 18 to 44 years and 45 to 65 years.

The researchers compared the average amount of fat each person gained each year to the amount of change in each individual's cholesterol.

"The important thing was the change across time," says Siervogel. "Generally speaking the faster fat is gained, the faster cardiovascular risk factors change in the direction of an unhealthy risk profile.

"From 5 to 15 percent of the variation in the annual change of cholesterol and LDL levels could be explained by the change in fatness," says Siervogel. In addition 5 to 10 percent of the decreases in HDL cholesterol levels were attributable to increases in body fat.

Men between 18 and 45 gained on average 1.25 pounds of fat per year, while men 45 to 65 gained an average of 0.82 pounds of fat per year. The age-related difference didn't hold true for women in the study. Both the older and younger groups of women gained an average of 1.1 pounds of fat per year, and changes in LDL and HDL levels were similar in both groups of women.

Changes in cholesterol were closely related to changes in body fat, rather than fat free mass, the researchers report. The study suggests that cholesterol levels appear to change in the same direction as changes in fatty weight gain or loss regardless of an individual's amount of body fat.

Body mass index doesn't always accurately reflect the amount of body fat, Siervogel says. "It doesn't look at how much of the weight is fat versus muscle mass. Men and women can have the same BMI, but women will have a much higher percentage of fat."

Co-authors are Wayne Wisemandle, M.A.; Michele Maynard, Ph.D.; Shumei S. Guo, Ph.D.; Alex F. Roche, Ph.D.; William C. Chumlea, Ph.D.; and Bradford Towne, Ph.D.

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Media advisory: Dr. Siervogel can be reached by phone at (937) 767-6915. (Please do not publish telephone number.)



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