Influence of the ACTN3 R577X genotype on the injury epidemiology of marathon runners

Authors: MORENO, VICTOR - Miguel Hernandez University; ARECES, FRANCISCO - University Camilo José Cela; RUIZ-VINCENTE, DIANA - University Camilo José Cela; ORDOVAS, JOSE - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; DEL COSO, JUAN - Universidad Rey Juan Carlos

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2019
Publication Date: 1/28/2020
Citation: Moreno, V., Areces, F., Ruiz-Vincente, D., Ordovas, J.M., Del Coso, J. 2020. Influence of the ACTN3 R577X genotype on the injury epidemiology of marathon runners. PLoS ONE. 15(1):e0227548. https://doi.org/10.1371/journal.pone.0227548.
DOI: https://doi.org/10.1371/journal.pone.0227548

Interpretive Summary: Long-distance running is predominantly an aerobic exercise and requires stamina. The ability to practice long-distance running successfully depends, in part, on individual biological factors defined by genetic characteristics. The same applies to the predisposition to suffer injuries during the practice of this activity. The aim of this work conducted by investigators in Spain and at the HNRCA in Boston was to determine the influence of genetic variability at one of the muscle-related genes, known as ACTN3, on injury incidence of marathoners. The type and conditions of sports injuries were documented for one year in a group of 139 marathoners. The results show that the probability of suffering a muscle injury after long-distance running was twice in those carrying the XX gene variant than those with the RR form of the gene. Future research should focus on the impact of genetics on people performing less strenuous forms of exercise.

Technical Abstract: A common single nucleotide polymorphism in the ACTN3 gene might result in the complete deficiency of alpha-actinin-3 (i.e., XX genotype). It has been found that ACTN3 XX individuals have several traits related to lessened muscle performance. This study aimed to determine the influence, if any, of ACTN3 genotypes on injury incidence of marathoners during the year preceding to participating in a competitive marathon race. Using a cross-sectional experimental design, the type and conditions of sports injuries were documented for one year in a group of 139 marathoners. Injuries were recorded following a consensus statement on injuries in Athletics. Afterward, ACTN3 genotyping was performed, and injury epidemiology was compared among RR, RX, and XX genotypes. The distribution of the RR/RX/XX genotypes was 28.8/42.8/23.5%, respectively. A total of 67 injuries were recorded. The frequency of marathoners that reported any injury during the previous year was not different across the genotypes (55.0/38.8/40.6%, P = 0.241). Although the overall injury incidence was not different among genotypes (2.78/1.65/1.94 injuries/1000 h of running, P = 0.084), the likelihood of suffering an injury was higher in RR than in RX (OR = 1.93: 95%CI = 0.87-4.30), and higher than in XX (OR = 1.79: 0.70-4.58). There was no difference in the conditions, severity, body location, time of year, or leading cause of injury among genotypes. However, XX presented a higher frequency of sudden-onset injuries (P = 0.024), and the OR for muscle-type injuries was 2.0 (0.51-7.79) times higher compared to RR runners. Although XX marathoners did not have a higher overall incidence of injury, the OR in these runners for muscle-type injuries was superior to RR and RX runners. The likelihood of suffering a muscle injury, especially with a sudden-onset, was twice in XX than in RR endurance runners.