Association of the matrix metalloproteinase 3 (MMP3) single nucleotide polymorphisms with tendinopathies: case-control study in high-level athletes.

BACKGROUND Matrix metalloproteinases (MMPs) play an important role in matrix remodelling, as well as in tendon integrity. Due to overuse, athletes often develop chronic tendinopathies. If not treated, they lead to severe impairment, even complete tendon ruptures. AIM The main purpose of this study was to investigate whether three functional polymorphisms within the MMP3 gene are associated with increased risk of developing tendinopathies in high-level Croatian athletes. METHODS We have recruited one hundred fifty-five (63 high-level athletes with diagnosed tendinopathies and 92 asymptomatic controls) unrelated Caucasians for this case-control genetic study. All participants were genotyped for three single nucleotide polymorphisms (SNP) within the MMP3 gene: rs591058 C/T, rs650108 A/G and rs679620 G/A using the pyrosequencing method. RESULTS The MMP3 rs650108 GG (P = 0.0074) and rs679620 AA (P = 0.0119) genotypes were significantly over-represented in cases compared with controls, while rs591058 TT (P = 0.0759), as well as haplotype variant T - G - A (P = 0.06), implicated that there is an indication of predisposition for tendinopathies. CONCLUSION These results support association between functional variants within the MMP3 gene and the risk of tendinopathies in high-level athletes. Further research is needed to replicate these results in a larger population.