Endurance exercise is associated with increased plasma cardiac troponin I in horses

Abstract

These data indicate that cardiac stress may occur in horses associated with endurance exercise. Future studies utilising echocardiograpy to assess cardiac function in horses with increased cTnI are warranted.

Influence of Cavalcade of Different Distances on the Serum Concentrations of the Cardiac Biomarkers Troponin I (Ctni) and Creatine Kinase Myocardial Band (CK-MB) in Horses

“…with exercise such as fitness status, electrolyte imbalances, and dehydration could not be determined from the results of this study. Increased concentrations of cTnI have also been reported in connection with high-intensity activity, short and moderate-duration exercise, and in endurance horses without signs of cardiac disease [11,12,13,14 ]. The causes of exerciseinduced cTnI concentrations are not clear.…”

“…Three other studies also showed an inverse relationship between exercise time or distance and post-exercise troponin concentration [13,21,32]. The researchers postulated that the younger, faster athletes competed harder and closer to their cardiovascular limits than other competitors and, therefore, may have been more likely to induce minor cardiac injury [21,32].…”

“…Correlations between the degree of myocardial infarction size and the release of cTnI have been shown in humans and dogs, and can be used as a prognostic indicator [23,24]. However, in horses, there is not a defined range for values considered modest vs. those considered severe, or what clinical diseases or mechanisms cause mild, modest and severe elevations [13]. In humans, serum cTnI concentrations increase after prolonged intense exercise such as marathon and ironman triathlon training [25,21].…”

“…One theory suggests that the increases in cTnI concentrations may be explained by mild hypoxia during exercise. The hypoxia could cause a change in the permeability of myocardium, resulting in the leakage of macromolecules into blood flow [11,12,13]. found that short periods of hypoxia can induce release of cTnI without cell death in rats Piper, et al [20].…”

“…cTnI is also increase with non-cardiac diseases that induces secondary cardiac involvement, as example with babesiosis and endotoxaemia [9,10]. Release of cTnI during and after exercise also has been described in equine athletes after racing or race training, endurance rides or treadmill exercise [11,12,14,13]. Creatine Kinase-Myocardial Band (CK-MB) is another cardiac biomarker that has been reported to increase with exercise and with chest pain in humans [15].…”