Human Genome and Stem Cell Research Center, University of São Paulo, São Paulo 05508-090, SP, Brazil.
Department of Molecular Biology and Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435 Moscow, Russia.
Cells. 2024 Jul 18;13(14):1212. doi: 10.3390/cells13141212.
The greater muscle fiber cross-sectional area (CSA) is associated with greater skeletal muscle mass and strength, whereas muscle fiber atrophy is considered a major feature of sarcopenia. Muscle fiber size is a polygenic trait influenced by both environmental and genetic factors. However, the genetic variants underlying inter-individual differences in muscle fiber size remain largely unknown. The aim of our study was to determine whether 1535 genetic variants previously identified in a genome-wide association study of appendicular lean mass are associated with the CSA of fast-twitch muscle fibers (which better predict muscle strength) in the m. vastus lateralis of 148 physically active individuals (19 power-trained and 28 endurance-trained females, age 28.0 ± 1.1; 28 power-trained and 73 endurance-trained males, age 31.1 ± 0.8). Fifty-seven single-nucleotide polymorphisms (SNPs) were identified as having an association with muscle fiber size ( < 0.05). Of these 57 SNPs, 31 variants were also associated with handgrip strength in the UK Biobank cohort ( = 359,729). Furthermore, using East Asian and East European athletic ( = 731) and non-athletic ( = 515) cohorts, we identified 16 SNPs associated with athlete statuses (sprinter, wrestler, strength, and speed-strength athlete) and weightlifting performance. All SNPs had the same direction of association, i.e., the lean mass-increasing allele was positively associated with the CSA of muscle fibers, handgrip strength, weightlifting performance, and power athlete status. In conclusion, we identified 57 genetic variants associated with both appendicular lean mass and fast-twitch muscle fiber size of m. vastus lateralis that may, in part, contribute to a greater predisposition to power sports.
较大的肌肉纤维横截面积（CSA）与较大的骨骼肌质量和力量有关，而肌肉纤维萎缩被认为是肌肉减少症的主要特征。肌肉纤维大小是一种多基因特征，受环境和遗传因素的影响。然而，个体间肌肉纤维大小差异的遗传变异仍知之甚少。我们的研究目的是确定先前在四肢瘦体重全基因组关联研究中发现的 1535 个遗传变异是否与 148 名活跃个体（19 名力量训练和 28 名耐力训练女性，年龄 28.0 ± 1.1；28 名力量训练和 73 名耐力训练男性，年龄 31.1 ± 0.8）股外侧肌快肌纤维 CSA 相关。鉴定出 57 个单核苷酸多态性（SNP）与肌肉纤维大小相关（<0.05）。在这些 57 个 SNP 中，有 31 个变体也与英国生物库队列中的握力相关（=359729）。此外，使用东亚和东欧的运动员（=731）和非运动员（=515）队列，我们鉴定出 16 个与运动员身份（短跑运动员、摔跤运动员、力量运动员和速度力量运动员）和举重表现相关的 SNP。所有 SNP 的关联方向相同，即增加瘦体重的等位基因与肌肉纤维 CSA、握力、举重表现和力量运动员身份呈正相关。总之，我们鉴定出与四肢瘦体重和股外侧肌快肌纤维 CSA 相关的 57 个遗传变异，这些变异可能部分导致对力量运动的更大倾向。
