Elevation of cardiac troponins measured after recreational resistance training

Abstract

BackgroundWhereas elevated cardiac troponin (cTn) concentrations i.e. above the 99th percentile of healthy reference population (recommended cutoff for the diagnosis of myocardial infarction) are well-documented in healthy individuals after prolonged and/or intensive exercises such as marathons, data on less-strenuous sports are scarce. Therefore, our aim was to investigate cTnI and cTnT release in response to recreational resistance training, here a single-bout of 1-h kettlebell workout. MethodsSerum samples were collected from 11 apparently healthy volunteers the previous day (pre-exercise), three hours after the kettlebell class (post-exercise), the next day and three days later. The aliquoted samples were analyzed with Abbott Laboratories' Architect high-sensitivity (hs)-cTnI assay (limit of detection, LoD=2ng/L), our 3+1-type cTnI assay free from cTn-specific autoantibody interference (LoD=3ng/L) and Roche Diagnostics' hs-cTnT assay (LoD=5ng/L). ResultsThe post-exercise cTn concentrations were significantly higher than the pre-exercise values (median 5.5–9.6ng/L vs. <LoD, P<0.05 for all) and they correlated strongly between the three assays (Spearman r=0.881–0.960, P<0.001 for all). Furthermore, a few post-exercise concentrations even exceeded the 99th percentile of Architect hs-cTnI (>26ng/L, n=2) and/or hs-cTnT (>14ng/L, n=4). The cTn concentrations returned to baseline during the three days of follow-up. ConclusionsOur study demonstrates abnormally elevated cTns with well-validated sensitive cTn assays after resistance training. This confirms that different kinds of recreational physical activity are yet another confounder that may affect the determination and use of 99th percentile reference values. Therefore, exercise-associated changes should be carefully addressed as part of the evaluation what is “normal cTn”.