Cardiac remodeling and global longitudinal strain in young male competitive athletes: A comparative study across different training modes

Objective: Athletic heart (AH) is the structural, and functional cardiac alterations depending on a training type, intensity and number of sports-related factors (SRF) in an athletic cohort.Global longitudinal strain (GLS) is the earlier marker of cardiac dysfunction and predicts adverse outcomes.In this study, we aimed to determine the phenotypes of AH in the athletes of different training types (TT) and relationship between the SRF and the GLS.Methods: In this cross-sectional study, 58 young competitive male athletes (aged 14-22) undergoing endurance (END) (n=15), resistance (RES) -22, and mixed (MIX) -21 trainings and 29 sedentary subjects (SED) were enrolled.We obtained total training time (TTT, months), weekly training load (WTL, hrs/week), and tournament participation for each athlete.Using transthoracic echocardiography (TTE) we evaluated all standard aortic dimensions, left heart chamber quantifications, left ventricular mass index (LVMI) and GLS.For statistical analysis we used the ANOVA/Kruskal-Wallis tests, and Chi-square/Fischer's exact tests and multiple linear regression analysis (MLA).Results: Athletes were matched by TTT, where the overall median was 42 (24-72) months (p=0.31),but WTL significantly differed with median values of 12 (8-22) h/wk (p0.001).Noteworthy, RES athletes exhibited the highest h/wk.Aortic dimensions and left cardiac chamber quantifications differed between groups (p<0.05).The END athletes exhibited higher aortic diameters, left atrial volume and left ventricular end-diastolic volume (p<0.05).The RES athletes showed the highest wall thickness and left ventricular mass (p0.001).Athletes of the MIX group showed modest changes in cardiac structural indices, however, still, these values were higher than in SED matches (p<0.05).Mean LVMI was 73.1 (17.1) g/m 2 with substantial variations among groups (p<0.001).Concentric remodeling was predominantly seen in the RES athletes.Median GLS was -21 (-19, -22)% and significantly differed between groups (p<0.001).MLR revealed the negative significant relation between WTL and GLS (unadjusted =-0.16,adjusted =-0.12, p=0.01, 95% CI =-0.212, -0.029), while age, TTT, LVMI did not affect GLS (p0.05). Conclusion:Our study emphasizes the diverse phenotypes of AH in the competitive athletes of different TT.The RES athletes have decreased GLS and thickened myocardium in contrast to other athletic groups and SED matches.Furthermore, higher WTL significantly decreases the GLS in athletes and may be a predictor of adverse outcomes in athletes.