CARDIAC BIOMARKERS FLUCTUATION IN RUNNERS OF MARATHONS, SEMI-MARATHONS AND UNTRAINED RUNNERS

INTRODUCTION: Regular exercise like running is one important part of the prevention program of cardiovascular disease. There are several studies on biomarker changes during marathons especially cardiac biomarkers have been studied and mild to moderate elevations have been described as a results of a running exercise Exact underlying mechanism for these biomarker elevations reflecting physiological or even pathobiological changes is unknown and less trained athletes might exhibit a higher risk compared to well trained. The aim of our study was to compare three cardiac biomarkers for ischemic condition , cardiac stretch and fibrotic processes were tested in different type of runners, trained marathon and semi-marathon runners and untrained runners before, directly after and 3 hours after the running exercise.
METHODS: 23 marathon runners, 15 semi-marathon runners <44.1±8.4yo> and 17 healthy sedentary subjects < 37± 4.4 yo> were enrolled in our study. Blood samples were taken just before , just after and 3 hours after the race, centrifuged, aliquoted and stored frozen at -80°C before further analysis. The study was approved by the Ethical Committee of our University Hospital. The analyses were performed on the Abbott ARCHITECT i2000SR for the hs cTnI, BNP and Gal-3 and on the C8000 for hs-cTnT and NTproBNP according to the manufacturer’s instructions for use.
RESULTS: In all 3 running groups there is an increase of cardiac biomarkers Troponin I, BNP, Galectin-3 and NT-ProBNP after completion of the physical exercise. Biomarkers increase is depending on the intensity and duration of the exercise and is higher in long distance marathon and semi-marathon runners compared to the control group with a 1 hour run. Cardiac biomarker levels between trained marathon and semi-marathon runners were not statistically different in the pre-exercise baseline samples for BNP, NT-Pro-BNP and Galectin-3. Compared to untrained runners only Troponin I levels were higher in baseline sample of marathon runners when compared to controls, cardiac Troponin T was less significant.
CONCLUSION: In conclusion, the question whether running exercise of different intensity could be harmful to the heart has no simple answer. We could show that running exercise can be associated with biochemical abnormalities that may reflect adverse consequences on the heart like possible micro necrosis, oxidative stress, fibrosis and myocardial stretch. With exception of Troponin where levels continue to raise after end of running, NPs and Gal-3 levels normalized relatively fast after the exercise. The possible harmful effect of longer term cardiac consequences of repeated intensive sport acitvities still needs to be demonstrated.