Changes in thigh muscle volume predict bone mineral density response to lifestyle therapy in frail, obese older adults
Changes in thigh muscle volume predict bone mineral density response to lifestyle therapy in frail, obese older adults
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DOI：
10.1007/s00198-013-2450-2
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发表时间：
2014-02-01
影响因子：
4
通讯作者：
Villareal, D. T.
中科院分区：
文献类型：
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作者：
Armamento-Villareal, R.;Aguirre, L.;Villareal, D. T.
我们研究了力量、肌肉质量和骨矿物质密度 (BMD) 与生活方式改变之间的关系。生活方式疗法包括运动、饮食、饮食加运动。通过限制热量饮食来诱导并维持体重较基线体重减轻 10%。运动可以减轻体重减轻引起的肌肉和骨骼损失。尽管节食和运动导致患者肌肉损失，但运动仍能提高力量。力量的变化与 BMD 的变化无关。然而，大腿肌肉体积的变化与髋部 BMD 相关，并可预测其变化。髋部 BMD 和去脂体重的损失是体弱、肥胖老年人生活方式治疗的主要并发症。然而，肌肉损失导致的机械应变损失的贡献尚不清楚。我们确定了大腿肌肉体积和肌肉力量的变化对体弱肥胖老年人 BMD 的影响，这些老年人正在接受生活方式治疗，旨在有意识地减肥（无论是否运动）。 107 名肥胖老年人被随机分为对照组、节食组、运动组和节食运动组，为期 1 年。通过磁共振成像测量大腿肌肉体积，通过DXA测量BMD，通过测力法测量膝盖力量，通过一次重复最大强度（1-RM）测量总强度，通过免疫测定测量骨标志物。饮食组的大腿肌肉体积减少（-6.2 +/- 4.8 %），运动组增加（2.7 +/- 3.1 %），但与饮食-运动组的对照组没有显着差异。臀部 BMD 的变化与大腿肌肉体积的变化相似。运动组（23 +/- 20 %；25 +/- 19 %）和饮食运动组（20 +/- 19 %；20.6 +/- 27 %）的膝关节伸展和屈曲增加，但对照组和饮食组没有变化。大腿肌肉体积的变化与髋部 BMD 的变化相关（r = 0.55，P = < 0.001），并且在考虑人口因素以及体重和体力活动变化后的多元回归分析中，大腿肌肉体积的变化是髋部 BMD 变化的独立预测因子（β = 0.12，P = 0.03）。 BMD 变化与膝关节力量、1-RM 和硬化蛋白变化之间没有相关性。大腿肌肉体积的变化可预测接受生活方式治疗的肥胖老年患者的髋部 BMD 变化。当饮食中加入运动时，运动可以减少大腿肌肉的流失，这可能在一定程度上解释了饮食+运动组中体重减轻引起的骨质流失的减少。
We studied the relationships among strength, muscle mass, and bone mineral density (BMD) with lifestyle change. Lifestyle therapy consisted of exercise, diet, and diet plus exercise. Diet was by caloric restriction to induce and maintain a weight loss of 10 % from baseline body weight. Exercise attenuated weight loss-induced muscle and bone losses. Exercise improved strength despite muscle loss in patients on diet and exercise. Changes in strength did not correlate with changes in BMD. However, changes in thigh muscle volume correlated with, and predicted changes in hip BMD.Losses of hip BMD and lean body mass are major complications of lifestyle therapy in frail, obese older adults; however, the contribution of mechanical strain loss from muscle loss is poorly defined. We determined the effect of changes in thigh muscle volume and muscle strength on BMD in frail, obese older adults undergoing lifestyle therapy aimed at intentional weight loss with or without exercise.One hundred seven obese older adults were randomized to control, diet, exercise, and diet-exercise groups for 1 year. Thigh muscle volume was measured by magnetic resonance imaging, BMD by DXA, knee strength by dynamometry, total strength by one-repetition maximum (1-RM), and bone markers by immunoassay.Thigh muscle volume decreased in the diet group (-6.2 +/- 4.8 %) and increased in the exercise group (2.7 +/- 3.1 %), while it was not significantly different from the control in the diet-exercise group. Changes in hip BMD followed similar pattern as those in thigh muscle volume. Knee extension and flexion increased in the exercise group (23 +/- 20 %; 25 +/- 19 %) and diet-exercise group (20 +/- 19 %; 20.6 +/- 27 %) but were unchanged in the control and diet groups. Changes in thigh muscle volume correlated with changes in hip BMD (r = 0.55, P = < 0.001) and were an independent predictor of changes in hip BMD (beta = 0.12, P = 0.03) in the multiple regression analyses after accounting for demographic factors and changes in weight and physical activity. There were no correlations between BMD changes and knee strength, 1-RM, and sclerostin changes.Changes in thigh muscle volume predict hip BMD changes in obese older patients undergoing lifestyle therapy. The effect of exercise in attenuating thigh muscle loss when added to diet may in part account for the reduction in weight loss-induced bone loss in the diet-exercise group.