METHODS: Multivariable linear regression analysis examined the relationship between circulating BCAAs and muscle mass/strength. Logistic regression analysis assessed the impact of circulating BCAAs and quartiles of BCAAs on sarcopenia risk. Subgroup analyses explored the variations in associations across age, and gender. Mediation analysis investigated the potential mediating effect of muscle mass on the BCAA-muscle strength relationship.
RESULTS: Among 108,017 participants (mean age: 56.40 ± 8.09 years; 46.23% men), positive associations were observed between total BCAA, isoleucine, leucine, valine, and muscle mass (beta, 0.56-2.53; p < 0.05) and between total BCAA, leucine, valine, and muscle strength (beta, 0.91-3.44; p < 0.05). Logistic regression analysis revealed that increased circulating valine was associated with a 47% reduced sarcopenia risk (odds ratio = 0.53; 95% confidence interval = 0.3-0.94; p = 0.029). Subgroup analyses demonstrated strong associations between circulating BCAAs and muscle mass/strength in men and individuals aged ≥ 60 years. Mediation analysis suggested that muscle mass completely mediated the relationship between total BCAA, and valine levels and muscle strength, partially mediated the relationship between leucine levels and muscle strength, obscuring the true effect of isoleucine on muscle strength.
CONCLUSIONS: This study suggested the potential benefits of BCAAs in preserving muscle mass/strength and highlighted muscle mass might be mediator of BCAA-muscle strength association. Our findings contribute new evidence for the clinical prevention and treatment of sarcopenia and related conditions involving muscle mass/strength loss.
方法:多变量线性回归分析了循环BCAA与肌肉质量/力量之间的关系。Logistic回归分析评估循环BCAAs和四分位数BCAAs对肌肉减少症风险的影响。亚组分析探讨了不同年龄的关联变化,和性别。中介分析研究了肌肉质量对BCAA-肌肉力量关系的潜在中介作用。
结果:在108,017名参与者中(平均年龄:56.40±8.09岁;46.23%的男性),观察到总BCAA,异亮氨酸,亮氨酸,缬氨酸,和肌肉质量(β,0.56-2.53;p<0.05)和总BCAA,亮氨酸,缬氨酸,和肌肉力量(β,0.91-3.44;p<0.05)。Logistic回归分析显示,循环缬氨酸的增加与肌肉减少症风险降低47%相关(比值比=0.53;95%置信区间=0.3-0.94;p=0.029)。亚组分析表明,男性和年龄≥60岁的个体的循环BCAA与肌肉质量/力量之间存在很强的关联。中介分析表明,肌肉质量完全介导了总BCAA,缬氨酸水平和肌肉力量,部分介导了亮氨酸水平和肌肉力量之间的关系,掩盖异亮氨酸对肌肉力量的真正影响。
结论:这项研究表明BCAA在保持肌肉质量/力量方面的潜在益处,突出的肌肉质量可能是BCAA-肌肉力量关联的媒介。我们的发现为临床预防和治疗肌肉减少症和涉及肌肉质量/力量丧失的相关疾病提供了新的证据。