NEW YORK (Reuters Health) - 'Bulking up' by athletes playing sports such as American football may lead to an increased risk for cardiovascular disease, study findings suggest.

"Our work demonstrates a higher prevalence of metabolic syndrome, an established cardiovascular risk factor, among retired National Football League (NFL) linemen," said Dr. Marc A. Miller, of Mount Sinai Medical Center, in New York. Football linemen are position players commonly of large body size.

A clustering of heart disease and diabetes risk factors including high blood pressure, low levels of 'good' cholesterol, high levels of blood lipids (fats), and elevated blood sugar and body weight make up the metabolic syndrome.

When Miller and colleagues compared metabolic syndrome rates among 510 retired NFL players, they found that nearly 60 percent of linemen had metabolic syndrome, compared with 30 percent of those playing other positions.

Moreover, greater than 85 percent of the linemen were obese, as opposed to half of the non-linemen, the researchers report in The American Journal of Cardiology.

Between February 2004 and June 2006, Miller and colleagues assessed metabolic syndrome factors among 164 linemen and 346 non-linemen who, at the time, were 54-years-old on average. Overall, they had been NFL players for about six years and had been retired for about 25 years.

Miller notes that previous research indicated increased rates of cardiovascular death among NFL linemen compared with non-linemen and the general population. Therefore, he and colleagues were not surprised to also find a higher prevalence of metabolic syndrome among football linemen.

"The NFL, like any employer, has an obligation to address the health concerns of its employees," Miller told Reuters Health. "Players will have to be educated about lifestyle modification in their post-professional years," he said.

Likewise, "Student athletes need to be educated about the potential long-term health consequences of 'bulking up' and should be discouraged from achieving unhealthy body weights," Miller said.