Kikuchi Naoki, Yoshida Shou, Min Seok-ki, Lee Kihyuk, Sakamaki-Sunaga Mikako, Okamoto Takanobu, Nakazato Koichi
Sports Training Center, Nippon Sport Science University, Tokyo, Japan.
Appl Physiol Nutr Metab. 2015 Apr;40(4):316-22. doi: 10.1139/apnm-2014-0346. Epub 2014 Nov 20.
Homozygosity for the common nonsense polymorphism R577X in the α-actinin-3 gene (ACTN3) causes complete α-actinin-3 deficiency in fast-twitch skeletal muscle fibers. This study investigated whether the ACTN3 R577X polymorphism affects fitness status using a battery of tests in a large Japanese cohort. In the present study, 1227 subjects (age: 25-85 years) were genotyped for the ACTN3 R577X polymorphism (rs1815739) using a TaqMan SNP genotyping assay (Applied Biosystems). All subjects were divided into 2 groups based on their age (<55 years and ≥55 years). All subjects completed a questionnaire about exercise habits and were subjected to a battery of tests to assess their fitness status (including grip strength test, chair stand test, and 8-foot walking test). A significant association between the ACTN3 R577X genotype and chair stand test performance was observed in the group of men ≥55 using ANCOVA adjusted for age and exercise habits (p = 0.036). The ACTN3 R577X genotype accounted for 2.5% of the variability in the results of the chair stand test among men in the ≥55 age group. Moreover, for the ≥55 age group, performance in the chair stand test was lower among those with the XX genotype than among those with the RR genotype (p = 0.024) or RX genotype (p = 0.005), unlike results for the <55 age group. No significant difference was noted for hand grip strength or 8-foot walking time. Thus, our results suggest that the ACTN3 R577X genotype is associated with lower-extremity muscle function in the Japanese population.
α-辅肌动蛋白-3基因（ACTN3）常见的无义多态性R577X的纯合性会导致快肌骨骼肌纤维中α-辅肌动蛋白-3完全缺失。本研究使用一系列测试，对一大群日本人群进行调查，以探究ACTN3 R577X多态性是否会影响健康状况。在本研究中，采用TaqMan SNP基因分型检测法（应用生物系统公司）对1227名受试者（年龄：25 - 85岁）的ACTN3 R577X多态性（rs1815739）进行基因分型。所有受试者根据年龄分为两组（<55岁和≥55岁）。所有受试者均完成了一份关于运动习惯的问卷，并接受了一系列测试以评估其健康状况（包括握力测试、椅子站立测试和8英尺步行测试）。在年龄和运动习惯经协方差分析调整后的≥55岁男性组中，观察到ACTN3 R577X基因型与椅子站立测试表现之间存在显著关联（p = 0.036）。在≥55岁年龄组男性中，ACTN3 R577X基因型占椅子站立测试结果变异性的2.5%。此外，对于≥55岁年龄组，与RR基因型（p = 0.024）或RX基因型（p = 0.005）的人相比，XX基因型的人在椅子站立测试中的表现更低，这与<55岁年龄组的结果不同。握力或8英尺步行时间未观察到显著差异。因此，我们的结果表明，在日本人群中，ACTN3 R577X基因型与下肢肌肉功能相关。
