Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults
Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults
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DOI：
10.1159/000101826
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发表时间：
2007-01-01
期刊：
影响因子：
3.5
通讯作者：
Evans, Ellen M.
中科院分区：
文献类型：
--
作者：
Misic, Mark M.;Rosengren, Karl S.;Evans, Ellen M.
背景资料：肌肉质量，力量和健身在老年人下肢身体功能（LEPF）中发挥作用;然而，这些关系仍然没有得到充分的表征。目的：本研究旨在探讨社区健康老年受试者的腿部无矿物质瘦体重（MFLMLEG），腿部肌肉质量（MFLMLEG标准化的腿部力量），肥胖，有氧健身和LEPF之间的关系。研究方法：55名老年人（69.3 +/- 5.5岁，36名女性，19名男性）使用等速测力计评估腿部力量，通过双能X线吸收法评估身体成分，通过跑步机最大耗氧量测试评估有氧健身。LEPF评估使用计算机动态姿势描记和楼梯上升/下降，定时上升和去的任务和7米步行有和没有障碍。结果如下：肌肉力量、肌肉质量和有氧适应性与静态LEPF测试类似地相关（r范围0.27 - 0.40，p < 0.05）;然而，独立预测因子的强度并不稳健，解释的方差范围为9 - 16%。肌肉质量是所有动态LEPF测试的最强相关性（r范围0.54 - 0.65，p < 0.001）。使用逐步线性回归分析，肌肉质量是动态身体功能的最强独立预测因子，解释了29 - 42%的方差（p < 0.001），而有氧健身或体脂量解释了5-6%的方差（p < 0.05），这取决于性能测量。结论：肌肉质量是最重要的预测因子，有氧健身和脂肪量是社区老年人LEPF的次要预测因子。这些发现支持了运动（尤其是力量训练）对于老年人优化身体成分以及维持力量和身体机能的重要性。版权所有（c）2007 S. Karger AG，巴塞尔。
Background: Muscle mass, strength and fitness play a role in lower-extremity physical function (LEPF) in older adults; however, the relationships remain inadequately characterized. Objective: This study aimed to examine the relationships between leg mineral free lean mass (MFLMLEG), leg muscle quality (leg strength normalized for MFLMLEG), adiposity, aerobic fitness and LEPF in community-dwelling healthy elderly subjects. Methods: Fifty-five older adults (69.3 +/- 5.5 years, 36 females, 19 males) were assessed for leg strength using an isokinetic dynamometer, body composition by dual energy X-ray absorptiometry and aerobic fitness via a treadmill maximal oxygen consumption test. LEPF was assessed using computerized dynamic posturography and stair ascent/descent, a timed up-and-go task and a 7-meter walk with and without an obstacle. Results: Muscle strength, muscle quality and aerobic fitness were similarly correlated with static LEPF tests (r range 0.27 - 0.40, p < 0.05); however, the strength of the independent predictors was not robust with explained variance ranging from 9 to 16%. Muscle quality was the strongest correlate of all dynamic LEPF tests (r range 0.54 - 0.65, p < 0.001). Using stepwise linear regression analysis, muscle quality was the strongest independent predictor of dynamic physical function explaining 29 - 42% of the variance (p < 0.001), whereas aerobic fitness or body fat mass explained 5-6% of the variance (p < 0.05) depending on performance measure. Conclusions: Muscle quality is the most important predictor, and aerobic fitness and fat mass are secondary predictors of LEPF in community-dwelling older adults. These findings support the importance of exercise, especially strength training, for optimal body composition, and maintenance of strength and physical function in older adults. Copyright (c) 2007 S. Karger AG, Basel.