Comparison of EPR Fe3+-Transferrin Versus Approved Clinical Chemistry Test for Serum Iron Measurements in Professional Ice Hockey Players and Nonathletic Controls

Abstract

This study aimed to evaluate occult abnormalities of iron turnover in elite professional athletes. Electron paramagnetic resonance (EPR) and in vitro test for the quantitative determination of iron in human serum on “Cobas Integra 400 Plus” (CI) Roche automatic analyzer were used to evaluate the iron turnover in professional ice hockey players from four teams of the Continental Hockey League (study group, n = 110) and in two different control groups. The first group consisted of nonathletic young men (healthy controls, n = 25). The second group included male and female patients with different pathological conditions (comparison group, n = 16). The data pairs were compared using linear regression analysis, EPR data versus CI measurements. In the control and the comparison groups, EPR Fe3+ data associated with transferrin were highly correlated with CI serum iron measurements (squared correlation coefficient, r2 = 0.95). In the study group, correlation of the EPR Fe3+ measurements with CI serum iron levels in different teams of ice hockey players was statistically less powerful (r2 ranged from 0.61 to 0.78). Acute-phase copper-containing protein ceruloplasmin serum levels determined by EPR are also reported. Acute-phase responses were undetectable in most hockey players within quarterly scheduled medical examinations. The EPR spectroscopy combined with the routine biochemical serum iron measurements enable to detect occult dysmetabolic changes in iron turnover during intensive physical exercises. The results obtained support the use of EPR spectroscopy in the sports medicine because it helps to avoid misinterpretation of personalized biochemical markers and could facilitate the proper monitoring of iron-targeted interventions.