Background

This cross-sectional study aimed to investigate the relationship of the ACTN3 genotype with thigh muscle volume and physical performance in older adults with sarcopenia or pre-sarcopenia.

Methods

Data from 64 older Japanese adults (mean age 74.4 ± 6.9 years, women 71.9%) with sarcopenia or pre-sarcopenia were analyzed. Sarcopenia and pre-sarcopenia were defined using the Asian Working Group for Sarcopenia. We collected oral mucosa samples to determine the ACTN3 genotype. Thigh muscle volumes were measured using magnetic resonance imaging. Physical performance was assessed using the usual and maximum gait speed, timed up and go test, and five-repetition sit-to-stand test. Muscle strength was assessed using grip strength.

Result

The ACTN3 genotype proportions were 20.3% for RR, 51.6% for RX, and 28.1% for XX. Participants with the RR genotype showed greater thigh muscle volume/ht² compared to those with the RX and XX ACTN3 genotypes (p < 0.05). The multiple linear regression analysis revealed that RX (p < 0.01) and XX (p < 0.01) ACTN3 genotypes, compared to RR, were associated with lower thigh muscle volume/ht² and with age, sex (reference; men), weight and maximum walking speed. There was no significant difference between physical performance and muscle strength between the ACTN3 genotypes.

Conclusion

The ACTN3 genotype of the X allele was associated with decreased thigh muscle volume compared to the ACTN3 genotype of RR in older adults with sarcopenia or pre-sarcopenia.

中文翻译：

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α-actinin-3 基因型与患有肌肉减少症或肌肉减少症前兆的老年人大腿肌肉体积和身体表现的关联

背景

这项横断面研究旨在调查 ACTN3 基因型与患有肌肉减少症或肌肉减少症的老年人的大腿肌肉体积和身体表现的关系。

方法

分析了来自 64 名患有肌肉减少症或肌肉减少症的日本老年人（平均年龄 74.4 ± 6.9 岁，女性 71.9%）的数据。少肌症和少肌症前期是使用亚洲少肌症工作组定义的。我们收集口腔黏膜样本以确定 ACTN3 基因型。使用磁共振成像测量大腿肌肉体积。使用通常和最大步态速度、定时起跑测试和五次重复坐站测试来评估身体表现。使用握力评估肌肉力量。

结果

RR 的 ACTN3 基因型比例为 20.3%，RX 为 51.6%，XX 为 28.1%。与具有 RX 和 XX ACTN3 基因型的参与者相比，具有 RR 基因型的参与者显示出更大的大腿肌肉体积/ht ^{2 (p < 0.05)。}多元线性回归分析显示，与 RR 相比，RX (p < 0.01) 和 XX (p < 0.01) ACTN3 基因型与较低的大腿肌肉体积/ht ²以及年龄、性别（参考；男性）、体重和最大步行速度。ACTN3基因型之间的体能和肌肉力量没有显着差异。

结论

在患有肌肉减少症或肌肉减少症的老年人中，与 RR 的 ACTN3 基因型相比，X 等位基因的 ACTN3 基因型与大腿肌肉体积减少有关。