CK-MM gene polymorphism does not influence the blood creatine kinase activity after exhaustive eccentric exercise

Gene variants, such as creatine kinase (CK) polymorphisms, have been suggested to explain the inter-individual CK response. However, this association is still unclear. Therefore, the purpose of this study was to analyze the association between the magnitudes of the CK response to exercise with the occurrence of muscle-CK-MM NcoI polymorphism in young healthy subjects. Blood CK activity was assessed in 70 subjects immediately before and 3, 24, 48, 72, 96, 120, 168 hours after an unusual and eccentric exhaustive exercise. Based on the amount of CK release by each subject, sample was distributed in quartiles being the genotype and allele frequency distribution compared among quartiles. Despite the inter-individual variability of CK response observed between subjects, there were no differences in genotype and allele frequencies among quartiles. The results allowed us to conclude that CK response after exhaustive eccentric exercise is not associated with CK-MM Ncol polymorphism. Key-words: Quartiles, genotype, inter-individual variability, muscle damage