Mateu Serra Prat, Research Unit, Hospital of Mataró, Carretera de Cirera s/n, 08304 Mataró, Barcelona, Spain, Tel. 34 93 741 77 30, Fax. 34 93 757 33 21, e-mail:
J Nutr Health Aging. 2019;23(1):96-101. doi: 10.1007/s12603-018-1129-y.
As a person ages, total body water (TBW), intracellular water (ICW), muscle mass and muscle strength tend to decline. The decline in ICW may reflect losses in the number of muscle cells but may also be responsible for less hydrated muscle cells.
To assess whether TBW and ICW are associated with muscle strength, functional performance and frailty in an aged population, independently of muscle mass.
Design: An observational cross-sectional study of community-dwelling individuals aged 75 years and older. TBW, ICW, fat mass, lean mass and muscle mass were assessed by bioelectrical impedance analysis, frailty status was measured according to Fried criteria, handgrip strength was measured using the hand-held JAMAR dynamometer, and functional performance was measured according to the Barthel index and gait speed.
A total of 324 subjects were recruited (mean age 80.1 years, 47.5% women). TBW and ICW were closely correlated with muscle mass in both sexes. ICW was also associated with Barthel score, gait speed and frailty in both sexes and with handgrip in men. Considerable variability in ICW was observed for the same muscle mass. Multivariate analysis showed a positive effect of ICW on handgrip, functional performance and gait speed and a protective effect of ICW on frailty, independently of age, sex, body mass index and number of comorbidities.
In elderly individuals with similar muscle mass, those with higher ICW had a better functional performance and a lower frailty risk, suggesting a protective effect of cell hydration, independently of muscle mass.
随着年龄的增长，人体总水量（TBW）、细胞内水（ICW）、肌肉质量和肌肉力量往往会下降。ICW 的减少可能反映了肌肉细胞数量的减少，但也可能导致肌肉细胞含水量减少。
评估在老年人群中，TBW 和 ICW 是否与肌肉力量、功能表现和虚弱状态相关，而与肌肉质量无关。
设计：一项针对 75 岁及以上社区居民的观察性横断面研究。通过生物电阻抗分析评估 TBW、ICW、脂肪量、瘦体量和肌肉量，根据 Fried 标准评估虚弱状态，使用手持 JAMAR 测力计评估握力，根据巴氏量表和步态速度评估功能表现。
共纳入 324 名受试者（平均年龄 80.1 岁，47.5%为女性）。TBW 和 ICW 与两性的肌肉质量密切相关。ICW 也与两性的巴氏量表评分、步态速度和虚弱状态以及男性的握力相关。对于相同的肌肉质量，ICW 存在相当大的变异性。多变量分析显示，ICW 对握力、功能表现和步态速度有积极影响，对虚弱有保护作用，与年龄、性别、体重指数和合并症数量无关。
在肌肉质量相似的老年个体中，ICW 较高者的功能表现更好，虚弱风险更低，提示细胞水合作用具有保护作用，与肌肉质量无关。
