Chiles Shaffer Nancy, Ferrucci Luigi, Shardell Michelle, Simonsick Eleanor M, Studenski Stephanie
Longitudinal Studies Section, Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, Maryland.
J Am Geriatr Soc. 2017 Mar;65(3):574-579. doi: 10.1111/jgs.14706. Epub 2016 Dec 26.
To derive lean mass cutpoints based on a less-conservative Foundation for the National Institutes of Health (FNIH) Sarcopenia Project Weakness cutpoint for grip strength (Weak ) and to assess their agreement with European Working Group on Sarcopenia in Older People (EWGSOP) and prediction of incident slow walking and mortality.
Longitudinal analysis.
Baltimore Longitudinal Study of Aging.
Individuals aged 65 and older (287 men, 258 women) with 2 to 10 years of follow-up.
Weakness was determined according to handgrip strength using a hand dynamometer, appendicular lean mass (ALM) using dual-energy X-ray absorptiometry, and walking speed according to 6-m usual pace walk speed. Analyses were performed using classification and regression tree analysis, Cohen's kappa, and Cox models.
Cutpoints derived from Weak for ALM (ALM ) were less than 21.4 kg in men and less than 14.1 kg in women and for ALM adjusted for body mass index (ALM/BMI ) were less than 0.725 in men and less than 0.591 in women. Kappas with EWGSOP were 0.65 for men and 0.75 for women for ALM and 0.34 for men and 0.47 for women for ALM/BMI . Men with Weak + ALM were twice as likely to develop slow walking as those not weak with normal ALM (Hazard ratio (HR) = 2.44, 95% confidence interval (CI) = 1.02-5.82). Under EWGSOP, men with weakness and low RALM were almost 3 times as likely to develop slow walking as those not weak with normal RALM (HR = 2.91, 95% CI = 1.11-7.62). Neither approach predicted incident slow walking in women.
The ALM cutpoints agree with EWGSOP and predict slow walking in men. Future studies should explore sex differences in the relationship between body composition and physical function and the effect of change in muscle mass on muscle strength and physical function.
基于美国国立卫生研究院（FNIH）肌肉减少症项目中握力的较宽松虚弱切点（Weak）得出瘦体重切点，并评估其与欧洲老年人肌肉减少症工作组（EWGSOP）的一致性以及对发生行走缓慢和死亡率的预测。
纵向分析。
巴尔的摩纵向衰老研究。
65岁及以上个体（287名男性，258名女性），随访2至10年。
使用握力计根据握力确定虚弱程度，使用双能X线吸收法测量四肢瘦体重（ALM），根据6米常规步速测量步行速度。使用分类和回归树分析、科恩kappa系数和Cox模型进行分析。
根据Weak得出的男性ALM切点（ALM）小于21.4千克，女性小于14.1千克；根据体重指数调整后的ALM（ALM/BMI）切点，男性小于0.725，女性小于0.591。ALM与EWGSOP的kappa系数男性为0.65，女性为0.75；ALM/BMI与EWGSOP的kappa系数男性为0.34，女性为0.47。Weak + ALM的男性发生行走缓慢的可能性是ALM正常且不虚弱男性的两倍（风险比（HR）= 2.44，95%置信区间（CI）= 1.02 - 5.82）。在EWGSOP标准下，虚弱且RALM低的男性发生行走缓慢的可能性几乎是RALM正常且不虚弱男性的3倍（HR = 2.91，95%CI = 1.11 - 7.62）。两种方法均未预测出女性会发生行走缓慢。
ALM切点与EWGSOP一致，并能预测男性行走缓慢。未来研究应探讨身体成分与身体功能关系中的性别差异以及肌肉量变化对肌肉力量和身体功能的影响。
