Polimorfismos genéticos associados à lesão muscular em jogadores de futebol profissional

Abstract

Evidence suggests that genetic polymorphism plays a mediating role in physiological and structural changes that may predispose soccer players to non-contact muscle injuries. However, the relationship between genetic variations, environmental factors, and muscle injuries still requires further investigation. In this context, this thesis aimed to investigate the association between the MuRF-1/TRIM63 (rs2275950) and ACTN3 R577X (rs1815739) genotypes and the occurrence of muscle injuries in professional soccer players. Independent studies were conducted, each with a specific objective, to explore various aspects of the relationship between these genetic biomarkers and muscle injuries in the sports context. The first study investigated the association between the genotypes of MuRF-1/TRIM63 and the occurrence of muscle injuries in professional soccer players. The second study analyzed whether muscle injury incidence rates vary according to playing positions and examined whether these rates differ among ACTN3 R577X genotypes in professional soccer players. The third study consisted of a systematic review to evaluate the effects of physical exercise on the MuRF-1/TRIM63 mRNA expression in humans. The results showed that the MuRF-1/TRIM63 genotypes (χ² = 2.19; p = 0.292), the dominant model (χ² = 1.04; p = 0.299), and the recessive model (χ² = 1.94; p = 0.208) did not present significant associations with muscle injuries in professional soccer players. On the other hand, during matches, players with the ACTN3 RR genotype exhibited a significantly higher incidence rate of muscle injuries compared to those with the ACTN3 XX genotype (RR vs. XX; 95% CI: 14.38 ± 67.10 vs. 0.00 ± 352.47, respectively; p = 0.016). Similarly, wide midfielders showed a significantly higher muscle injury incidence rate compared to central defenders (WM vs. CD; 95% CI: 0.00 ± 43.00 vs. 0.00 ± 493.42, respectively; p = 0.010). However, no significant differences were observed in muscle injury incidence rates among ACTN3 R577X genotypes or across playing positions during training sessions. In the systematic review, an analysis of the 46 selected studies revealed that physical exercise modulates the MuRF-1 mRNA expression in humans. Resistance exercise (RE) and endurance exercise (EE) induce transient increases in MuRF-1 mRNA expression, with peaks occurring between 40 minutes and 4 hours post-stimulus. Combined exercise protocols (RE + EE) lead to significant increases approximately 3 hours after exercise. The molecular response was influenced by variables such as exercise order and intensity, muscle contraction mode, sex, age, and fitness level. It was concluded that MuRF-1/TRIM63 genotypes were not significantly associated with muscle injuries in professional soccer players. However, the ACTN3 RR genotype was linked to a higher muscle injury incidence rate during matches, as were wide midfielders compared to central defenders. These findings suggest that genetic factors and playing position may influence the risk of muscle injuries in professional soccer, particularly in competitive settings. Furthermore, the findings of the systematic review reinforce the modulatory role of physical exercise on the MuRF-1 mRNA expression, highlighting the importance of specific training variables and individual characteristics to better understand the molecular mechanisms that influence performance and muscle recovery in humans.