People who run marathons are more likely to have higher levels of a protein linked to heart attacks, according to researchers at The University of Western Australia.
UWA's Associate Professor Daniel Fatovich and UWA Clinical Associate Professor Samuel Vasikaran, a biochemist, are two of the co-authors of a paper published in the Medical Journal of Australia last week, which studied 92 runners who competed in the 2007 Perth Marathon.
Dr Fatovich, an emergency medicine specialist at Royal Perth Hospital, said elevated levels of the heart protein troponin were commonly used as an indicator when diagnosing a heart attack.
"We found raised troponin levels in a third of those who completed the marathon, with the strongest predictors being weight loss and an increase in creatinine levels. Creatinine is a measure of kidney function," he said. "This suggests that the kidneys are working hard to clear the extra troponin from the body.
"What was interesting was that the marathon runners were not adversely affected by these elevated levels of troponin - it didn't seem to cause any health issues for them. It seems that in a healthy exercising population, troponin is routinely released from the heart muscle after periods of increased demand on the heart."
Of the 346 entrants in the marathon, the researchers enrolled 92 runners (27 per cent), of whom 88 (96 per cent) finished the race and took part in the pre and post-race surveys and blood tests.
Of those who took part in the study, 71 per cent were male while the mean age was 43 years and mean body mass index (BMI) was 24.1. They had trained on a mean of 4.5 days per week, running a mean of 60km per week in the three months before the race.
They had previously completed a mean of 9.5 marathons, with one participant running his 100th marathon and 26 per cent were competing in their first marathon.
The paper's co-authors are Royal Perth Hospital Registrars Kelley Hubble and Jonathon Grasko.
Dr Fatovich said the researchers were very grateful for the support of the WA Marathon Club.
View the article at http://www.mja.com.au/public/issues/190_02_190109/hub10697_fm.html