Exploring the Association Between CD36 rs1761667 Polymorphism and Susceptibility to Non-Contact Tissue Injuries in
El Mokhtar El Ouali1, Jihan Kartibou2, Juan Del Coso3
1Sports Science Research Team, Institute of Sports Sciences, Hassan I University, Settat 26002, Morocco.
Abstract:
Background: Non-contact tissue injury in elite athletes is influenced by multiple factors, including genetic predisposition. Although previous research has identified several genetic markers associated with injury susceptibility, the role of the CD36 (cluster of differentiation 36) gene, a key regulator of fatty acid transport into skeletal muscle and other vital tissues, remains unexplored in this context. A single-nucleotide polymorphism in the CD36 gene (rs1761667) involves an A-to-G substitution (with three genotypes = AA and GG homozygotes and AG heterozygotes), and previous data have reported that individuals carrying the AA genotype of the CD36 gene show reduced expression of the CD36 protein and poorer lipid metabolism. Additionally, it has been recently found that the frequency of the AA genotype is significantly lower in elite cyclists compared to field hockey players. No previous study has examined the association between the CD36 rs1761667 polymorphism and athlete injury risk. Therefore, the aim of this study was to investigate the potential association between the CD36 rs1761667 polymorphism and non-contact tissue injury susceptibility in elite Moroccan cyclists and field hockey players. Methods: Forty-three elite Moroccan male athletes, including 19 cyclists and 24 national team field hockey players, volunteered for this study. Non-contact tissue injuries during the 2022/2023 sports season have been recorded. Genotyping of the CD36 rs1761667 polymorphism was carried out using Sanger sequencing. Chi-square tests were used to analyze the Hardy-Weinberg equilibrium and compare the genotypes and characteristics of athletes with and without non-contact injuries. Results: During the 2022/2023 sports season, 21.05% of cyclists (4 out of 19) and 33.33% of field hockey players (8 out of 24) experienced non-contact tissue injuries. The genotypic frequency was similar in the injured and non-injured groups among cyclists (χ2 and p not calculated because "AA = 0" in both groups), field hockey players (χ2 = 3.30, p = 0.19), and all athletes (χ2 = 1.73, p = 0.41). Additionally, the dominant model of the CD36 rs1761667 polymorphism (AA+AG vs. GG) did not reveal a significant risk of non-contact injuries among cyclists (OR: 1.20, 95% CI: 0.13-19.09, p > 0.9999), field hockey players (OR: infinity, 95% CI: 0.23-infinity, p = 0.53), and all athletes (OR: 2.75, 95% CI: 0.32-34.12, p = 0.65). Furthermore, the recessive model (AA vs. AG+GG) did not demonstrate any effect on the risk of non-contact injuries in cyclists (OR and 95% CI not calculated, p > 0.9999), field hockey players (OR: 0.33, 95% CI: 0.05-2.40, p = 0.38), and all athletes (OR: 0.55, 95% CI: 0.10-2.60, p = 0.69). Conclusions: This study suggests that the association between specific genotypes (AA, AG, and GG) or alleles (A and G) of the CD36 gene and susceptibility to non-contact tissue injuries in Moroccan cycling and field hockey players is uncertain. Given the small sample size, further studies will be needed to explore and confirm these findings.
