Ancestral contribution of the muscle-specific creatine kinase (CKM) polymorphism rs4884 in the knee osteoarthritis risk: a preliminary study

Abstract

Introduction/Objectives Articular cartilage and periarticular muscle tissues are strongly affected during knee osteoarthritis (OA). Creatine kinase (CK) is an enzyme expressed in several tissues, but the isoform CK-MM is specific of skeletal muscle, and its serum concentration is used as a biomarker of muscle damage. Genetic variants of theCKMgene have been associated with various pathologies, but to date, there are no reports of association with OA. Due to the rs4884 polymorphism being well represented in the Mexican population, it is used as an ancestry informative marker; thus, the goal of this preliminary report was to evaluate the association of this polymorphism in primary knee OA Mexican patients. Method Eighty-seven patients with primary knee OA were compared with 107 healthy controls. Serum CK-MM was determined using the dot blot system, and genotyping was performed using the OpenArray system. Logistic regression models were used to assess the association between the rs4884 polymorphism and OA susceptibility adjusting by gender, age, and body mass index. Results There were no significant differences in serum CK-MM values between patients and controls. The GG genotype and the G allele had a higher frequency in the control group compared with the OA group (24.3% vs. 12.6%, OR = 0.34, 95% CI = 0.14-0.84,P = 0.019; and 40.2% vs. 28.2%, OR = 0.51, 95% CI = 0.32-0.82,P = 0.005, respectively). Conclusions Our results suggest a protection role of the rs4884 polymorphism against knee OA development; further studies are required to confirm it.