Impact of Iron and Homocysteine Levels on T Peak-to-End Interval and Tp-e/QT Ratio in Elite Athletes.

Abstract

Electrocardiography (ECG) is frequently used in preparticipation evaluation of competitive athletes. Repolarization heterogeneities on ECG is a well-known indicator for malignant ventricular arrhythmias and sudden cardiac death. We aimed to investigate the effect of iron and homocysteine levels on arrhythmogenic indicators, T peak-to-end (Tp-e) interval, and Tp-e/QT ratio in elite athletes. A total of 72 players (48 football and 24 basketball) with a mean age of 25.4 ± 5.0 years were included to the analysis. Blood biochemistry, homocysteine level, and iron parameters (transferrin saturation and serum iron) were obtained by standard methods. Duration of QRS, QT interval, and Tp-e interval were measured manually on the precordial leads and Tp-e/QT ratio was calculated. Baseline demographic and clinical characteristics of the study population were compared in two groups according to the median value of Tp-e/QT = 0.219. Both iron and transferrin saturations were higher in the above median group (P = 0.001 and P = 0.002, respectively), however, homocysteine levels were not statistically different among two groups (P = 0.405). In correlation analysis, both serum iron and transferrin saturation were significantly correlated with Tp-e interval (r = 0.368; P = 0.001 and r = 0.394; P = 0.00, respectively) and Tp-e/QT ratio (r = 0.357; P = 0.002 and r = 0.372; P = 0.001, respectively). Multiple stepwise regression analysis revealed that transferrin saturation was an independent predictor of Tp-e interval and Tp-e/QT ratio (β = 0.325; P = 0.002 and β = 0.372; P = 0.001, respectively). This study showed an independent relationship between iron status and Tp-e interval and Tp-e/QT ratios of elite sport players which were also not correlated with serum homocysteine levels.