Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States of America.
Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, United States of America.
PLoS One. 2021 Feb 2;16(2):e0245680. doi: 10.1371/journal.pone.0245680. eCollection 2021.
This study tested the hypothesis that sarcopenia and its constituent components, reduced lean muscle mass and impaired motor function, are associated with reduced survival and increased risk of incident disabilities.
1466 community-dwelling older adults underwent assessment of muscle mass with bioelectrical impedance analysis (BIA), grip strength, gait speed and other components of physical frailty and annual self-report assessments of disability. We used Cox proportional hazards models that controlled for age, sex, race, education and height to examine the associations of a continuous sarcopenia metric with the hazard of death and incident disabilities.
Mean baseline age was about 80 years old and follow-up was 5.5 years. In a proportional hazards model controlling for age, sex, race, education and baseline sarcopenia, each 1-SD higher score on a continuous sarcopenia scale was associated with lower hazards of death (HR 0.70, 95%CI [0.62, 0.78]), incident IADL (HR 0.80,95%CI [0.70, 0.93]), incident ADL disability (HR 0.80 95%CI [71, 91]) and incident mobility disability (HR 0.81, 95%CI [0.70, 0.93]). Further analyses suggest that grip strength and gait speed rather than muscle mass drive the associations with all four adverse health outcomes. Similar findings were observed when controlling for additional measures used to assess physical frailty including BMI, fatigue and physical activity.
Motor function is the primary driver of the associations of sarcopenia and physical frailty with diverse adverse health outcomes. Further work is needed to identify other facets of muscle structure and motor function which together can identify adults at risk for specific adverse health outcomes.
本研究检验了以下假设，即肌少症及其组成部分（肌肉质量减少和运动功能受损）与降低的生存率和增加的残疾发生率有关。
1466 名居住在社区的老年人接受了生物电阻抗分析（BIA）评估肌肉质量、握力、步态速度和身体虚弱的其他组成部分以及每年的残疾自我报告评估。我们使用 Cox 比例风险模型，控制年龄、性别、种族、教育程度和身高，来检查连续肌少症指标与死亡风险和残疾发生率的关联。
平均基线年龄约为 80 岁，随访时间为 5.5 年。在一个比例风险模型中，控制年龄、性别、种族、教育程度和基线肌少症，连续肌少症量表上每增加 1 个标准差得分与降低的死亡风险相关（HR 0.70，95%CI [0.62，0.78]）、IADL 新发残疾（HR 0.80，95%CI [0.70，0.93]）、ADL 残疾新发（HR 0.80 95%CI [71，91]）和移动性残疾新发（HR 0.81，95%CI [0.70，0.93]）。进一步的分析表明，握力和步态速度而不是肌肉质量驱动着与所有四个不良健康结果的关联。当控制 BMI、疲劳和体力活动等用于评估身体虚弱的其他措施时，也观察到了类似的发现。
运动功能是肌少症和身体虚弱与多种不良健康结果关联的主要驱动因素。需要进一步的工作来确定肌肉结构和运动功能的其他方面，这些方面可以一起识别有特定不良健康结果风险的成年人。
