Extracellular Water May Mask Actual Muscle Atrophy During Aging
Extracellular Water May Mask Actual Muscle Atrophy During Aging
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DOI：
10.1093/gerona/glq001
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发表时间：
2010-05-01
影响因子：
5.1
通讯作者：
Oda, Shingo
中科院分区：
文献类型：
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作者：
Yamada, Yosuke;Schoeller, Dale A.;Oda, Shingo
背景资料。骨骼肌组织含有大量的水，分为细胞外水(ECW)和细胞内水(ICW)两部分。由于ECW可能与肌肉力量没有直接关系，我们假设，从肌肉体积中剔除ECW将加强与肌肉力量的相关性。共有119名年龄在20-88岁的健康男性参与了这项研究。测量膝关节等长伸展力量、垂直跳跃和从椅子上站立作为腿部肌肉力量和力量的指标。通过人体测量(皮褶和周长测量)和节段性多频生物阻抗谱(S-BIS)测量小腿局部瘦体积(LV)、总水分(TW)、内脏重量(ICW)和外周血流量(ECW)。然后计算ECW/TW和ICW/TW比值。尽管ICW和LV指数随着年龄的增长而显著下降(p<；.001)，但ECW没有显著变化(p=.134)。因此，ECW/TW比率随着年龄的增长而显著增加(p<；.001)(年轻人，27.0+/-2.9%；老年人，34.3+/-4.9%；老年，37.2+/-7.0%)。通过在我们的模型中加入ICW/TW比率进行调整，显著改善了LV指数和力量相关测量之间的相关性，并且与独立于LV指数的力量相关测量相关(p<；.001)。小腿ECW/TW比值随年龄增长而增加。结果表明，ECW相对于ICW和LV的扩张掩盖了实际肌细胞随年龄增长而萎缩的现象。
Background. Skeletal muscle tissue holds a large volume of water partitioned into extracellular water (ECW) and intracellular water (ICW) fractions. As the ECW may not be related to muscle strength directly, we hypothesized that excluding ECW from muscle volume would strengthen the correlation with muscle strength.Methods. A total of 119 healthy men aged 20-88 years old participated in this study. Knee isometric extension strength, vertical jump, and standing from a chair were measured as indices of muscle strength and power in the lower extremities. The regional lean volume (LV), total water (TW), ICW, and ECW in the lower leg were estimated by anthropometry (skinfold and circumference measurements) and segmental multifrequency bioelectrical impedance spectroscopy (S-BIS). Then, we calculated the ECW/TW and ICW/TW ratios.Results. Although ICW and the LV index decreased significantly with age (p < .001), no significant changes in ECW were observed (p = .134). Consequently, the ECW/TW ratio increased significantly (p < .001) with age (young adult, 27.0 +/- 2.9%; elderly, 34.3 +/- 4.9%; advanced elderly, 37.2 +/- 7.0%). Adjusting for this by including the ICW/TW ratio in our models significantly improved the correlation between the LV index and strength-related measurements and correlated with strength-related measurements independently of the LV index (p < .001).Conclusions. The ECW/TW ratio increases in the lower leg with age. The results suggest that the expansion of ECW relative to ICW and the LV masked actual muscle cell atrophy with aging.