MONDAY, June 2, 2008 (HealthDay News) -- Black football players are twice as likely as whites to have abnormal electrocardiograms (ECGs), a new study finds.
But that doesn't mean they are at greater risk of heart disease, experts add.
The study of almost 2,000 athletes, done at the National Football League Invitational Camp from 2000 to 2005, found abnormal ECG patterns in 30 percent of black players and 13 percent of whites, noted a report in the June 10 issue of the Journal of the American College of Cardiology.
But "abnormal" doesn't necessarily mean "unhealthy," said Dr. Barry J. Maron, director of the Hypertrophic Cardiomyopathy Center of the Minneapolis Heart Institute Foundation, a member of the research team.
"The criteria we have always used for normality are based on data from white people, and it turns out that black and white people are not identical in this regard," Maron said.
And that unusual pattern of the ECG, which records the electrical waves that cause the heart muscle to pump, need not be a barrier to a long sports career, said Dr. Abraham Friedman, a clinical associate professor of medicine at the University of Pittsburgh, who has served as a cardiology advisor at marathon races and other events. Friedman noted that Wilt Chamberlain, the all-time National Basketball Association star, has such a pattern.
"Black athletes' ECGs may be more abnormal than white athletes ECGs, but when you put them together with a full evaluation, these changes may not speak [to] disease," Friedman said.
The NFL study was started and led by Dr. Anthony Magalski of the Mid-America Heart Institute, team physician for the NFL's Kansas City Chiefs.
"There has been for many years the idea that there are racial differences in the expression of the ECG in normal people as well as those with heart disease," said Maron. "None of it had ever been proven. This is the first to show differences in healthy young people."
Maron said he regarded the study results as an argument against routine cardiac screening of young athletes. "These data would suggest that that would be confusing if not chaotic," he said. "If you use the ECG as a screening tool, the ECG in blacks are more likely to be abnormal. That would raise the possibility of heart disease more frequently -- an unbalanced situation. Black athletes are more likely to be judged incorrectly to have heart disease."
Friedman said he favored such screening, but only if the differences among blacks and whites are taken into account.
A second study in the same issue of the journal found another black-white cardiac difference. The study, led by Dr. Sanjay Sharma of Kings College Hospital, London, compared 300 nationally ranked European black athletes from all sports with 300 matched white athletes and found a greater thickness of the wall of the left ventricle, the heart chamber that pumps blood to the body, in the black athletes. Such left ventricular hypertrophy, as it is called, is regarded as a sign of heart disease.
But the study also challenges that idea -- at least as far as healthy young athletes are concerned, Friedman said. "Black athletes hearts can be thicker than white athletes hearts and still be normal," he believes.
Finally, another study by Turkish and Spanish researchers pointed to a very real consequence for health from a long and punishing sports career.
Reporting in the June 3 issue of Annals of Internal Medicine, researchers found a high rate of pituitary hormone deficiency in Turkish boxers. The deficiency was greatest among those who had the longest careers in the ring, the researchers said, suggesting that head trauma may have caused the problem.
The electrocardiogram is explained by the U.S. Library of Medicine