College of Physical Education, University of Brasília, Brasília, Brazil.
Int J Sports Med. 2011 Jan;32(1):66-72. doi: 10.1055/s-0030-1267229. Epub 2010 Nov 11.
This study examined the association between ACE I/D and ACTN3 R577X polymorphisms and muscle-related phenotypes and their adaptation to resistance training in older women. Volunteers (n=246;age=66.7 ± 5.5 years) underwent quadriceps strength assessment using isokinetics and fat-free mass by dual energy X-ray absorptiometry. 79 volunteers performed 24 weeks of resistance training and 75 were studied as controls. Genotypes were identified by standard procedures. No associations were observed for muscle strength for either gene, but volunteers carrying the D/D genotype presented higher appendicular fat-free mass compared to the I-allele carriers (6.3 ± 0.1 vs. 6.1 ± 0.1 kg/m (2)). The X-allele carriers presented higher relative fat-free mass when compared to homozygous R/R (16.3 ± 0.1 vs. 15.9 ± 0.1 kg/m (2)). All fat-free mass variables were significantly greater for carriers of both X/X and D/D genotypes. In response to RT, only the I-allele carriers significantly increased fat-free mass and a significant training × genotype interaction was noted. These findings do not support a pivotal role for the studied polymorphisms in determining muscle strength in older women, but suggest a modest role in fat-free mass determination. Of note, the results provide a novel insight that these genetic variations may interact to determine muscle mass in older women.
本研究旨在探讨 ACE I/D 和 ACTN3 R577X 多态性与肌肉相关表型及其对老年女性抗阻训练适应的关系。志愿者（n=246；年龄=66.7±5.5 岁）采用等动测力法评估股四头肌力量，采用双能 X 射线吸收法测定去脂体重。79 名志愿者进行了 24 周的抗阻训练，75 名志愿者作为对照组进行研究。通过标准程序确定基因型。两种基因与肌肉力量均无相关性，但与携带 I 等位基因的志愿者相比，携带 D/D 基因型的志愿者四肢去脂体重更高（6.3±0.1 比 6.1±0.1 kg/m(2)）。与纯合 R/R 相比，X 等位基因携带者的相对去脂体重更高（16.3±0.1 比 15.9±0.1 kg/m(2)）。与携带 X/X 和 D/D 基因型的志愿者相比，所有去脂体重变量均显著更高。仅 I 等位基因携带者在抗阻训练后去脂体重显著增加，且存在训练×基因型的交互作用。这些发现不支持所研究的多态性在决定老年女性肌肉力量中的关键作用，但提示其在去脂体重决定中起适度作用。值得注意的是，这些结果提供了一个新的见解，即这些遗传变异可能相互作用，决定老年女性的肌肉质量。
