Background: Endurance exercise is frequently associated with cardiac troponin (cTn) concentrations, otherwise corresponding to minor myocardial infarction. However, research on the underlying mechanisms has been limited because of assay restraints in the low concentration range.
Methods and results: Using the pre-commercial, highly sensitive hs-cTnT assay, cTnT concentrations were measured in samples from recreational runners obtained before and after running 5 km (trained, n = 43/untrained, n = 122), 15 km (n = 38), 21 km (n = 10), and 42 km (n = 85) (all trained). The percentage of runners with elevated cTnT concentrations after the run increased with running distance (0, 11, 13, 40, and 86%), in contrast to NT-proBNP (2, 7, 0, 0, 5). Median (IQR) cTnT post-run concentrations were 0.004 microg/L (0.003), 0.006 microg/L (0.008), 0.010 microg/L (0.006), 0.014 microg/L (0.019), and 0.030 microg/L (0.029), respectively.
Conclusions: We found, using a novel hs-cTnT assay, the distance of recreational competitive running to be positively related to asymptomatic increases in cTnT post-run concentrations. In contrast, NT-proBNP showed no increase. In addition, the data indicated that a relatively short running distance of 5 km resulted in cTnT release of untrained participants, in contrast to trained participants, which underlines the necessity of sufficient training. Further effort is needed to clarify the significance of exercise-induced cardiac biomarker elevations.