Genetic Variants and Hamstring Injury in Soccer: An Association and Validation Study

PURPOSEThis study aimed to investigate the association of candidate single nucleotide polymorphisms (SNP) with noncontact hamstring muscle injuries in elite soccer players and to create and validate a model to assess the risk of hamstring injury. METHODSA total of 107 elite male outfield players were prospectively followed for six seasons. Players were genotyped for 37 SNP previously investigated in relation to musculoskeletal injuries. The association of SNP, previous injury, age, level of play, position, and anthropometric data with 129 hamstring injuries (413 observations) was investigated in the discovery phase (2010–2015), and a multivariable Cox frailty model was created using forward selection. The model’s discriminative ability was tested in the validation phase (2015–2016, 31 injuries, 98 observations) using Harrell’s C index. RESULTSFive SNP were found to be significantly associated with hamstring injury in a multivariable modelmatrix metalloproteinase 3 rs679620 (A vs G, hazard ratio [HR] = 2.06, 95% confidence interval [CI] = 1.51–2.81), tenascin C rs2104772 (A vs T, HR = 1.65, 95% CI = 1.17–2.32), interleukin 6 rs1800795 (GG vs GC + CC, HR = 1.68, 95% CI = 1.11–2.53), nitric oxide synthase 3 rs1799983 (G vs T, HR = 1.35, 95% CI = 1.01–1.79), and hypoxia-inducible factor-1α rs11549465 (CC vs CT, HR = 2.08, 95% CI = 1.00–4.29). Age also entered the model (≥24 vs