应用 D-creatine 稀释法估计 4 岁儿童的骨骼肌量。
Estimation of skeletal muscle mass in 4-year-old children using the D-creatine dilution method.
机构信息
Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada.
Centre for Global Child Health, Hospital for Sick Children, Toronto, ON, Canada.
出版信息
Pediatr Res. 2023 Sep;94(3):1195-1202. doi: 10.1038/s41390-023-02587-1. Epub 2023 Apr 10.
BACKGROUND
Given limited experience in applying the creatine-(methyl-D) (DCr) dilution method to measure skeletal muscle mass (SMM) in young children, the feasibility of deployment in a fielding setting and performance of the method was assessed in a cohort of 4-year-old children in Dhaka, Bangladesh.
METHODS
Following DCr oral dose (10 mg) administration, single fasting urine samples were collected at 2-4 days (n = 100). Twenty-four-hour post-dose collections and serial spot urine samples on days 2, 3 and 4 were obtained in a subset of participants (n = 10). Urinary creatine, creatinine, DCr and D-creatinine enrichment were analyzed by liquid chromatography-tandem mass spectrometry. Appendicular lean mass (ALM) was measured by dual-energy x-ray absorptiometry and grip strength was measured by a hand-held dynamometer.
RESULTS
SMM was measured successfully in 91% of participants, and there were no adverse events. Mean ± SD SMM was greater than ALM (4.5 ± 0.4 and 3.2 ± 0.6 kg, respectively). Precision of SMM was low (intraclass correlation = 0.20; 95% CI: 0.02, 0.75; n = 10). Grip strength was not associated with SMM in multivariable analysis (0.004 kg per 100 g of SMM; 95% CI: -0.031, 0.038; n = 91).
CONCLUSIONS
The DCr dilution method was feasible in a community setting. However, high within-child variability in SMM estimates suggests the need for further optimization of this approach.
IMPACT
The D3-creatine (D3Cr) stable isotope dilution method was considered a feasible method for the estimation of skeletal muscle mass (SMM) in young children in a community setting and was well accepted among participants. SMM was weakly associated with both dual-energy x-ray absorptiometry-derived values of appendicular lean mass and grip strength. High within-child variability in estimated values of SMM suggests that further optimization of the D3Cr stable isotope dilution method is required prior to implementation in community research settings.
背景
由于在将肌酸-（甲基-D）（DCr）稀释法应用于测量幼儿骨骼肌量（SMM）方面经验有限，因此在孟加拉国达卡的一组 4 岁儿童中评估了该方法在实地部署中的可行性及其性能。
方法
在口服 DCr 剂量（10mg）后，100 名儿童中有 100 名在 2-4 天内采集了单次空腹尿液样本。在一部分参与者（n=10）中，在 24 小时后采集了尿液样本，并在第 2、3 和 4 天采集了尿液样本。通过液相色谱-串联质谱法分析尿液中的肌酸、肌酐、DCr 和 D-肌酸丰度。通过双能 X 射线吸收法测量四肢瘦体重（ALM），通过手持测力计测量握力。
结果
91%的参与者成功测量了 SMM，没有不良事件。平均 SMM（4.5±0.4kg）明显大于 ALM（3.2±0.6kg）。SMM 的精度较低（组内相关系数=0.20；95%置信区间：0.02，0.75；n=10）。在多变量分析中，握力与 SMM 无关（每 100g SMM 增加 0.004kg；95%置信区间：-0.031，0.038；n=91）。
结论
DCr 稀释法在社区环境中是可行的。然而，SMM 估计值的个体内变异性较高表明需要进一步优化该方法。
影响
D3-肌酸（D3Cr）稳定同位素稀释法被认为是一种可行的方法，可用于在社区环境中估算幼儿的骨骼肌量（SMM），并得到了参与者的认可。SMM 与四肢瘦体重和握力的双能 X 射线吸收法测量值均有微弱关联。SMM 估计值的个体内变异性较高表明，在将 D3Cr 稳定同位素稀释法应用于社区研究环境之前，需要进一步优化该方法。
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