A Pilot Study on the Prediction of Non-Contact Muscle Injuries Based on R577X and I/D Polymorphisms in Professional Soccer Athletes.

Muscle injuries are among the main reasons for medical leavings of soccer athletes, being a major concern within professional teams and their prevention associated with sport success. Several factors are associated with a greater predisposition to injury, and genetic background is increasingly being investigated. The aim of this study was to analyze whether R577X and I/D polymorphisms are predictors of the incidence and severity of muscle injury in professional soccer athletes from Brazil, individually and in association. Eighty-three professional athletes from the first and second divisions of the Brazilian Championship were evaluated regarding the polymorphisms through blood samples. Nighty-nine muscle injuries were identified during the seasons of 2018, 2019 and 2020 and categorized according to severity. XX individuals had a higher frequency of severe injuries compared to the RX and RR genotypes ( = 0.001), and in the dominant model (compared to RX+RR), with < 0.001. The trend -value test showed an increased number of injuries/season following the order XX > RX > RR ( = 0.045). Those with the II genotype had almost 2 fold the number of injuries per season compared to those with the ID+DD genotypes ( = 0.03). Logistic regression showed that the polymorphisms are predictors of the development of severe injury ( R577X model with = 0.004, R: 0.259; I/D model with = 0.045, R: 0.163), where XX individuals were more likely to suffer from severe injury (OR: 5.141, 95% CI: 1.472-17.961, = 0.010). The combination of the 577X allele and the II genotype showed an increased number of injuries per season, enhanced by 100% (1.682 injuries/season versus 0.868 injuries/season, = 0.016). Our findings suggest that both polymorphisms R577X and I/D (and their interaction) are associated with the susceptibility and severity of non-contact muscle injury in soccer players.