Effect of ACTN3 R577X Genotype on Injury Epidemiology in Elite Endurance Runners.

Jorge Gutiérrez-Hellín,Millán Aguilar-Navarro,Gabriel Baltazar-Martins,Carlos Ruiz-Moreno,Jesús Oliván,Juan Del Coso

doi:10.3390/genes12010076

Abstract

The p.R577X polymorphism (rs1815739) in the ACTN3 gene causes individuals with the ACTN3 XX genotype to be deficient in functional α-actinin-3. Previous investigations have found that XX athletes are more prone to suffer non-contact muscle injuries. This investigation aimed to determine the influence of the ACTN3 R577X polymorphism in the injury epidemiology of elite endurance athletes. Using a cross-sectional experiment, the epidemiology of running-related injuries was recorded for one season in a group of 89 Spanish elite endurance runners. ACTN3 R577X genotype was obtained for each athlete using genomic DNA samples. From the study sample, 42.7% of athletes had the RR genotype, 39.3% had the RX genotype, and 18.0% had the XX genotype. A total of 96 injuries were recorded in 57 athletes. Injury incidence was higher in RR runners (3.2 injuries/1000 h of running) than in RX (2.0 injuries/1000 h) and XX (2.2 injuries/1000 h; p = 0.030) runners. RR runners had a higher proportion of injuries located in the Achilles tendon, RX runners had a higher proportion of injuries located in the knee, and XX runners had a higher proportion of injuries located in the groin (p = 0.025). The ACTN3 genotype did not affect the mode of onset, the severity, or the type of injury. The ACTN3 genotype slightly affected the injury epidemiology of elite endurance athletes with a higher injury rate in RR athletes and differences in injury location. However, elite ACTN3 XX endurance runners were not more prone to muscle-type injuries.

Highlights

The status of elite athlete requires many hours of strenuous training per week that can impose severe physiological and mechanical stress on the human body, leading to sports injuries
There were no differences in the distribution of athletes with/without injury across the different ACTN3 genotypes in the whole sample or when analyzing the subsamples of male and female elite endurance athletes (Table 2)
The ACTN3 genotype did not affect the proportion of time loss/medical attention injuries, the severity of the injury, the distribution of training and competition injuries, the proportion of recurrent injuries, the mode of onset, or the possible cause that led to the injury

Summary

Introduction

The status of elite athlete requires many hours of strenuous training per week that can impose severe physiological and mechanical stress on the human body, leading to sports injuries For this reason, injury is an inherent feature of elite sport [1], and injury prevention has become a key aspect of every conditioning program. Endurance running is a sports discipline with an elevated injury incidence due to the high mechanical load produced by weight-bearing and the high running mileage necessary to prepare for endurance competitions [2] For this reason, a high proportion of injuries in elite endurance runners are muscle or tendon overuse injuries, and the main sites of injury location are lower leg and knee [3,4]. Genetics might play a role in the predisposition to injury in some athletes [6], the variations in genes associated with muscle and tendon proteins [7]

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