Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, and.
Division of Pulmonary, Allergy and Critical Care Medicine, Columbia University Medical Center, New York, New York.
Ann Am Thorac Soc. 2021 Sep;18(9):1464-1474. doi: 10.1513/AnnalsATS.202007-796OC.
Sarcopenia is associated with disability and death. The optimal definition and clinical relevance of sarcopenia in lung transplantation remain unknown. To assess the construct and predictive validity of sarcopenia definitions in lung transplant candidates. In a multicenter prospective cohort of 424 lung transplant candidates, we evaluated limited (muscle mass only) and expanded (muscle mass and quality) sarcopenia definitions from the European Working Group on Sarcopenia in Older People 2 (EWGSOP2), the Foundation for the National Institutes of Health (FNIH), and a cohort-specific distribution-based lowest quartile definition. We assessed construct validity using associations with conceptually related factors. We evaluated the relationship between sarcopenia and frailty using generalized additive models. We also evaluated associations between sarcopenia definitions and key pretransplant outcomes, including disability (quantified by the Lung Transplant Valued Life Activities scale [range, 0-3; higher scores = worse disability; minimally important difference, 0.3]) and waitlist delisting/death, by multivariate linear and Cox regression, respectively. Sarcopenia prevalence ranged from 6% to13% by definition used. The limited EWGSOP2 definition demonstrated the highest construct validity, followed by the expanded EWGSOP2 definition and both limited and expanded FNIH and lowest quartile definitions. Sarcopenia exhibited a linear association with the risk of frailty. The EWGSOP2 and expanded lowest quartile definitions were associated with disability, ranging from 0.20 to 0.25 higher Lung Transplant Valued Life Activities scores. Sarcopenia was associated with increased risk of waitlist delisting or death by the limited and expanded lowest quartile definitions (hazard ratio [HR], 3.8; 95% confidence interval [CI], 1.4-9.9 and HR, 3.5; 95% CI, 1.1-11.0, respectively) and the EWGSOP2 limited definition (HR, 2.8; 95% CI, 0.9-8.6) but not with the three other candidate definitions. The prevalence and validity of sarcopenia vary by definition; the EWGSOP2 limited definition exhibited the broadest validity in lung transplant candidates. The linear relationship between low muscle mass and frailty highlights sarcopenia's contribution to frailty and also questions the clinical utility of a sarcopenia cut-point in advanced lung disease. The associations between sarcopenia and important pretransplant outcomes support further investigation into using body composition for candidate risk stratification.
肌肉减少症与残疾和死亡有关。在肺移植中，肌肉减少症的最佳定义和临床相关性仍不清楚。评估肌肉减少症定义在肺移植候选者中的结构和预测有效性。在一个由 424 名肺移植候选者组成的多中心前瞻性队列中，我们评估了欧洲老年人肌肉减少症工作组 2（EWGSOP2）、美国国立卫生研究院基金会（FNIH）的有限（仅肌肉质量）和扩展（肌肉质量和质量）肌肉减少症定义，以及基于队列的分布最低四分位定义。我们使用与概念相关的因素来评估结构有效性。我们使用广义加性模型评估肌肉减少症与虚弱之间的关系。我们还通过多元线性和 Cox 回归分别评估了肌肉减少症定义与关键移植前结局（包括由肺移植价值活动量表[范围，0-3 分；得分越高表示残疾越严重；最小有意义差异，0.3]量化的残疾和等待名单除名/死亡）之间的关系。使用不同定义时，肌肉减少症的患病率从 6%到 13%不等。有限的 EWGSOP2 定义显示出最高的结构有效性，其次是扩展的 EWGSOP2 定义以及有限的和扩展的 FNIH 和最低四分位定义。肌肉减少症与虚弱的风险呈线性相关。EWGSOP2 和扩展最低四分位定义与残疾相关，肺移植价值活动量表的得分分别高出 0.20 至 0.25。肌肉减少症与等待名单除名/死亡的风险增加相关，有限和扩展的最低四分位定义的危险比（HR）分别为 3.8（95%置信区间[CI]，1.4-9.9 和 HR，3.5；95%CI，1.1-11.0）和 EWGSOP2 有限定义（HR，2.8；95%CI，0.9-8.6），但与其他三个候选定义无关。肌肉减少症的患病率和有效性因定义而异；EWGSOP2 有限定义在肺移植候选者中表现出最广泛的有效性。肌肉质量低与虚弱之间的线性关系突出了肌肉减少症对虚弱的贡献，也对晚期肺病中肌肉减少症切点的临床实用性提出了质疑。肌肉减少症与重要移植前结局之间的关联支持进一步研究使用身体成分进行候选者风险分层。
