Cardiac biomarker changes in athletes: correlations with resting and exercise testing parameters

Introduction Necroenzymes and peptide fragments serve as key diagnostic markers in the diagnosis and follow-up of certain acute and chronic cardiovascular diseases. Their associations with long-term sports adaptation remain partially understood. Methods During sports cardiology screening, we analysed resting levels of high-sensitivity troponin T (TnT), creatine kinase (CK), lactate dehydrogenase (LDH), and NT-proBNP. All the samples were collected at least 12 hours after the last training or competition. The results of the athletes were compared with a healthy sedentary non-athlete control group. We investigated correlations of these parameters with bioimpedance-derived body composition (skeletal muscle mass: SMM, fat-free mass: FFM, body fat%: BFP), echocardiographic (left ventricular end-diastolic diameter: LVEDD, septal wall thickness: SW, posterior wall thickness: PW), and cardiopulmonary exercise testing (CPET) performance indicators (maximal absolute oxygen uptake: absVO2max, maximal relative oxygen uptake: relVO2max, maximal ventilation: VEmax). The statistical analysis was performed in Python development environment. Results We analyzed data from 1051 athletes (male: 54%, age: 21.5 ± 8.4 years, training: 14.8 ± 6.5 hours/week) and 104 sedentary non-athletes (male: 59%, age: 29.7 ± 10.9 years). Athletes showed higher CK (203 [135-312] vs. 120 [83-177] U/L, p<0.001) and LDH (186 [159-243] vs. 152 [138-177] U/L, p<0.001) values, as well as lower NT-proBNP levels (24 [11-46] vs. 28 [18-58] pg/mL, p<0.05), with similar TnT results (5 [4-7] vs. 5 [3-6] ng/L, p=0.19) compared to sedentary individuals. CK correlated (p<0.001) with LVEDD (r=0.33), SW (r=0.28), PW (r=0.28), absVO2max (r=0.45), relVO2max (r=0.35), VEmax (r=0.38), BFP (r=-0.41), SMM (r=0.45), and FFM (r=0.44). The TnT correlated (p<0.001) with LVEDD (r=0.23), SW (r=0.24), PW (r=0.26), absVO2max (r=0.37), relVO2max (r=0.34), VEmax (r=0.31), BFP (r=-0.41), SMM (r=0.38), and FFM (r=0.37). NT-proBNP correlated (p<0.001) with SW (r=-0.25), PW (r=-0.21), absVO2max (r=-0.37), relVO2max (r=-0.23), VEmax (r=-0.34), BFP (r=0.27), SMM (r=-0.36), and FFM (r=-0.35). In the case of the LDH values, no significant correlation was found with the examined parameters. Conclusion Based on our results, resting levels of some biomarkers change in response to regular physical activity. Our findings indicate that resting levels of certain biomarkers are associated with multiple body composition, echocardiographic, and CPET performance indicators of sports adaptation, as CK and TnT were higher, while NT-proBNP was lower with better sports adaptation. These markers may be suitable for monitoring sports adaptation, with established athlete-specific reference ranges.