Rising troponin levels after exercise can help identify those at risk of cardiovascular disease or early death; the findings do not mean exercise is harmful.
While exercise provides a variety of health benefits and is often related with reducing the risk of cardiovascular disease, prolonged or intensive exercise may lead to an increase in cardiac biomarkers in the blood, according to researchers.
Research suggests that troponin is a regulatory protein in heart muscle cells, which can leak into blood vessels when there is heart damage. Elevated protein levels can be used to diagnose a heart attack. Physiologists of Radboud University Medical Center and John Moores University aimed to measure the implications of increased troponin levels after exercise.
Blood samples were taken from 725 walkers before and after prolonged walking exercise in order to determine troponin concentration. In the years following, the researchers annually checked in with the patients to determine their cardiovascular health and survival status.
"After 10 years of research we can finally answer this important question," researcher Thijs Eijsvogels, said in a statement. "Of the participants who had a high troponin concentration after walking, 27% developed severe cardiovascular disease or died during follow-up, while this was the case for only 7% in the group of participants with a low troponin concentration after walking. This study shows for the first time that an exercise-related increase in troponin is clinically relevant."
Despite these results, the researchers emphasized that this does not necessarily mean that people who exercise are at risk—in actuality, troponin concentration after exercise could potentially be used for early detection of patients susceptible to cardiovascular disease.
"You can consider exercise as a stress test for the heart, and walkers with a high troponin concentration may be suffering from subclinical cardiovascular disease that has not yet been diagnosed. Therefore, our findings may contribute to early identification of susceptible individuals in the future, so that appropriate treatment can be started,” concluded Eijsvogels. "It is simply not the case that exercise is harmful to your heart. People who exercise regularly live 3 to 6 years longer than those who do not, so getting enough exercise remains important for everyone."
Aengevaeren VL, Hopman MTE, Thompson PD, et al. Exercise-induced cardiac troponin increase and incident mortality and cardiovascular events [published online August 12, 2019]. Circulation. doi.org/10.1161/CIRCULATIONAHA.119.041627.