MONDAY, June 5, 2006 (HealthDay News) -- Fifty percent of retired National Football League linemen have metabolic syndrome, and they are 50 percent more likely to have an enlarged heart than retired non-linemen, two new studies show.
That unhealthy combination puts the lineman at greater risk for heart disease, contend researchers from Mount Sinai Medical Center in New York City. They presented their findings Monday at the American Society of Echocardiography annual scientific sessions, in Baltimore.
NFL linemen often weigh more than 300 pounds.
"When these players retire, they don't think about how big they are, their eating habits," explained researcher Dr. Lori Croft, associate director of the echocardiography lab at Mount Sinai Heart and an assistant professor of medicine at Mount Sinai School of Medicine. "This puts them more at risk for metabolic syndrome."
In the first study, researchers used heart ultrasound (echocardiography) to look at the hearts of 303 retired NFL players. They found that many of the linemen had enlarged hearts, while players of other positions didn't.
An enlarged heart is often a sign of heart disease, which can develop into heart failure.
"We found that 50 percent more linemen were likely to have an enlarged heart compared to their non-linemen counterparts," Croft said.
Why linemen are particularly susceptible to developing an enlarged heart is not clear. "There is something about linemen, the way they train or whether they have bigger BMIs (body mass index, a ratio of weight to height) that give them a 50 percent chance of having an enlarged heart," Croft said.
In the second study, the same researchers looked at the presence of metabolic syndrome in 382 retired NFL players. Metabolic syndrome is a group of risk factors for heart disease, such as high blood pressure, obesity, high cholesterol and high blood sugar.
"In the general population, there is about a 20 percent incidence of metabolic syndrome," Croft said. "In our cohort of retired NFL players, almost 51 percent of linemen had metabolic syndrome compared to non-linemen."
Among non-linemen, the prevalence of metabolic syndrome was less than that seen among the general population, Croft noted.
Croft thinks these problems are the result of linemen not changing their lifestyle after retirement. These players continue to maintain their weight while not maintaining their previous level of physical activity, she said.
One expert thinks that increasing your weight to play a sport can lead to health problems later on.
"These studies underscore the fact that striving for success on the playing field sometimes ironically leads to worse overall health," said Dr. Byron K. Lee, an assistant professor of cardiology at the University of California, San Francisco. "A similar phenomenon has been also seen in sumo wrestlers."
These studies should not be interpreted as meaning that being a NFL lineman causes cardiovascular disease, Lee said. "The fact is that many former NFL linemen are overweight. This is not surprising after many years of being told to eat more and more because larger size, even due to fat, can be advantageous for linemen," he said.
"We already know that obesity is linked to most, if not all, of the outcomes found in this study. The bottom line, whether you are an NFL lineman or not, is to stay lean," Lee said.
Another expert thinks there is a message here for non-athletes, too.
"The message here is not that exercise, per se, is harmful," said Dr. David L. Katz, an associate professor of public health and director of the Prevention Research Center at Yale University School of Medicine. "Rather, extremes tend to take a toll on the body."
Linemen are expected to attain extreme bulk, and that is more and more a combination of muscle and fat, Katz said. "A great mass of body muscle tends to increase the bulk of heart muscle, too. A thick heart has long been recognized as a risk factor for heart disease," he said.
"Like the rest of us, football players are increasingly subject to obesity," Katz said. "An excess of muscle-building may bulk up the heart, while an excess of fat sets one up for insulin resistance and diabetes when professional athleticism ceases. The combination is a lethal threat."
There are clearly implications here for the coaching and conditioning of professional athletes, Katz said. "One would hope the demands of the game, and demands of health, can be put into a better balance. For the rest of us, the message is that moderation tends to define the path toward optimal health."
The American Heart Association can tell you more about metabolic syndrome.