Physical activity and cardiac markers: part 1

Aim. The paper identifies the effect of heavy physical training on the levels of the most common cardiac markers in the diagnosis of cardiovascular diseases (cardiac troponin, fatty acid-binding protein, copeptin) and discusses the possible mechanisms for changing serum levels of these markers. Materials and methods. The paper presents the analysis of Russian and foreign publications on this topic indexed in PubMed/Medline, Embase and eLibrary (RSCI) databases. Results. The data obtained in healthy people and athletes indicate increased cardiac markers (cardiac troponins; fatty acid-binding protein, copeptin) in response to exercise. Their post-exercise levels in athletes may exceed the reference values up to 10 or more times. The release mechanisms of these cardiac markers have not been fully explored. The following mechanisms may be responsible for increased cardiac troponins during heavy exercise: cross-reactivity with skeletal troponin isoforms; release of the cytosolic fraction of troponins through extracellular vesicles; increased membrane permeability of cardiac myocytes; degradation of troponin proteins into peptide fragments and their release through intact cardiac myocytes. The release mechanisms of fatty acid-binding protein during exercise are likely to be associated with increased membrane permeability. Increased copeptin levels during exercise may be explained by the effect of stress reactions and changes in electrolyte balance on the hypothalamus and pituitary gland. Conclusion. The clinical importance of increased levels of cardiac markers is considered controversial. Some authors negate the negative effect of heavy exercise on the myocardium, while others believe that excessive physical activity can lead to fibrosis, heart failure and an increased risk of sudden death. Therefore, more research is needed.