ACTN3 genotype is associated with increases in muscle strength in response to resistance training in women
ACTN3 genotype is associated with increases in muscle strength in response to resistance training in women
复制标题
DOI：
10.1152/japplphysiol.01139.2004
复制
发表时间：
2005-07-01
影响因子：
3.3
通讯作者：
Hoffman, EP
中科院分区：
文献类型：
--
作者：
Clarkson, PM;Devaney, JM;Hoffman, EP
α-辅肌动蛋白3（ACTN 3）基因编码肌纤维Z盘的蛋白质，并且ACTN 3的多态性导致该蛋白质的完全丧失。已发现ACTN 3基因型（R577 X）与澳大利亚精英运动员的表现相关（Yang N，麦克阿瑟DG，Gulbin JP，Hahn AG，Beggs AH，Easteal S和North K. Am J Genet 73：627 - 631，2003）。我们研究了ACTN 3基因型与肌肉大小（通过磁共振成像（MRI）测量的肱二头肌横截面积）、肘屈肌等长（MVC）和动态（1-重复最大（1-RM））力量之间的关系，（N = 247）和女性（N = 355）在8个研究中心之一参加了为期12周的非优势臂标准化肘屈/伸肌阻力训练计划。我们发现男性中ACTN 3 R577 X基因型和肌肉表型之间没有关联。然而，在校正体重和年龄后，ACTN 3 577 X等位基因（XX）纯合子女性的基线MVC低于杂合子（P < 0.05）。在调整体重和年龄后，突变等位基因（577 X）纯合子的女性在阻力训练后表现出比纯合子野生型（RR）更大的绝对和相对1-RM增益（P < 0.05）。有一个趋势，剂量反应与基因型，这样的增益是最大的XX和最少的RR。在至少一个种族亚群（高加索人，亚洲人）中验证了显著的相关性，并且与训练量无关。约2%的基线MVC和训练后1-RM力量增加归因于ACTN 3基因型（似然比检验P值，P = 0.01），表明ACTN 3是导致肌肉性能和运动适应性遗传变异的许多基因之一。
The alpha-actinin 3 (ACTN3) gene encodes a protein of the Z disk of myofibers, and a polymorphism of ACTN3 results in complete loss of the protein. The ACTN3 genotype (R577X) has been found to be associated with performance in Australian elite athletes ( Yang N, MacArthur DG, Gulbin JP, Hahn AG, Beggs AH, Easteal S, and North K. Am J Hum Genet 73: 627 - 631, 2003). We studied associations between ACTN3 genotype and muscle size [cross-sectional area of the biceps brachii via magnetic resonance imaging (MRI)] and elbow flexor isometric (MVC) and dynamic [1-repetition maximum (1-RM)] strength in a large group of men ( N = 247) and women ( N = 355) enrolled in a 12-wk standardized elbow flexor/ extensor resistance training program of the nondominant arm at one of eight study centers. We found no association between ACTN3 R577X genotype and muscle phenotype in men. However, women homozygous for the ACTN3 577X allele (XX) had lower baseline MVC compared with heterozygotes ( P < 0.05) when adjusted for body mass and age. Women homozygous for the mutant allele ( 577X) demonstrated greater absolute and relative 1-RM gains compared with the homozygous wild type (RR) after resistance training when adjusted for body mass and age ( P < 0.05). There was a trend for a dose-response with genotype such that gains were greatest for XX and least for RR. Significant associations were validated in at least one ethnic subpopulation ( Caucasians, Asians) and were independent of training volume. About 2% of baseline MVC and of 1-RM strength gain after training were attributable to ACTN3 genotype ( likelihood-ratio test P value, P = 0.01), suggesting that ACTN3 is one of many genes contributing to genetic variation in muscle performance and adaptation to exercise.