Lunardi Cláudia C, Lima Ricardo M, Pereira Rinaldo W, Leite Tailce K M, Siqueira Ana B M, Oliveira Ricardo J
College of Physical Education, University of Brasilia, SMU/QRS/RCG, Rua E, Casa 504, Brasília, Distrito Federal, Brazil,
Age (Dordr). 2013 Dec;35(6):2477-83. doi: 10.1007/s11357-013-9526-y. Epub 2013 Apr 2.
A previous genome-wide association study suggested that polymorphisms in the thyrotrophin-releasing hormone receptor (TRHR) gene contribute to fat-free mass (FFM) variation. The aim of the present study was to examine the association between polymorphisms in the TRHR gene with FFM and muscle strength in older women. Volunteers (n = 241; age = 66.65 ± 5.5 years) underwent quadriceps strength assessment using isokinetics and fat-free mass by dual-energy X-ray absorptiometry. TRHR polymorphisms and ancestry-informative markers were genotyped through standard procedures. No significant difference was observed for rs7832552. Regarding the rs16892496, ANCOVA revealed that appendicular fat-free mass (AFFM) and relative AFFM were significantly different between groups (p = 0.04 and p = 0.05, respectively). Individuals carrying A/A and A/C genotypes respectively showed, on average, an extra 1 kg and 900 g of AFFM when compared to C/C genotype carriers. Also, the C/C genotype group presented a significantly higher chance to have reduced muscle strength. The observations presented here provide further evidence that the rs16892496 polymorphism in the TRHR gene may play a role in FFM variation. Moreover, the results bring the novel insight that this genetic variant can present a modest contribution to muscle strength in older women.
先前的一项全基因组关联研究表明，促甲状腺激素释放激素受体（TRHR）基因的多态性与去脂体重（FFM）的变化有关。本研究的目的是探讨老年女性TRHR基因多态性与FFM及肌肉力量之间的关联。志愿者（n = 241；年龄 = 66.65 ± 5.5岁）通过等速肌力测试进行股四头肌力量评估，并采用双能X线吸收法测量去脂体重。通过标准程序对TRHR多态性和祖先信息标记进行基因分型。rs7832552未观察到显著差异。对于rs16892496，协方差分析显示，各组间上肢去脂体重（AFFM）和相对AFFM存在显著差异（分别为p = 0.04和p = 0.05）。与携带C/C基因型的个体相比，携带A/A和A/C基因型的个体平均分别多1 kg和900 g的AFFM。此外，C/C基因型组肌肉力量降低的可能性显著更高。本研究结果进一步证明，TRHR基因中的rs16892496多态性可能在FFM变化中起作用。此外，研究结果还带来了新的见解，即这种基因变异可能对老年女性的肌肉力量有一定贡献。
