The Mots-c K14Q Polymorphism Is Associated With Muscular Strength In Older Korean Adults

PURPOSE: To investigate the relationship between an East Asian-specific m.1382A > C polymorphism in the mitochondrial open reading frame of the 12S rRNA-c (MOTS) and muscular strength in older Korean adults. METHODS: The study included 408 older Korean adults (70 men and 338 women) aged 65 years and older who were voluntarily recruited from our local community. Total DNA was extracted from whole-blood samples. The m.1382A > C polymorphism (rs111033358) was genotyped using a custom TaqMan® SNP Genotyping Assay with a 7500 real-time PCR system. Total body composition including fat and lean mass was assessed with dual x-ray absorptiometry. Appendicular skeletal muscle (ASM) mass in kg was calculated as the sum of muscle mass in the arms and legs. Handgrip strength (HGS) in kg was measured in the right and left hands with a hand dynamometer. Comparisons of the measured parameters were made using both one-way ANOVA and ANCOVA with age as a covariate. RESULTS: Genotype analysis showed that C allele was more common in men than in women (11.5% vs. 4.7%, p = .030) in this study population. ANOVA showed that men carrying C allele had significantly higher means in ASM (21.6 ± 3.0 vs. 19.5 ± 2.2 kg, p = .018), ASM/height2 (7.76 ± 0.76 vs. 7.14 ± 0.62 kg/m2, p = .012), lean mass (53.3 ± 6.2 vs. 46.5 ± 4.0 kg, p < .001), left HGS (33.3 ± 5.0 vs. 28.9 ± 4.0 kg, p = .009), and right HGS (35.6 ± 5.3 vs. 30.9 ± 4.3 kg, p = .009) than men carrying A allele. ANCOVA showed that the mean differences in ASM (p = .017), ASM/height2 (p = .011), lean mass (p < .001), left HGS (p = .010), and right HGS (p = .009) between men carrying A and C alleles remained statistically significant even after adjusting for age. By contrast, no statistically significant differences in the measured parameters were found between women carrying A and C alleles. CONCLUSIONS: The current findings of the study suggest that the c allele carriers of the m.1382A > C polymorphism may have some protection against age-related loss of muscle mass and strength in older Korean men only. This study was supported by Research Grant (Grant No. KSSO201901) from Korean Society for the Study of Obesity and the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education (grant number: NRF-2022R1I1A1A01066469).