Positive energy balance is associated with accelerated muscle atrophy and increased erythrocyte glutathione turnover during 5 wk of bed rest
Positive energy balance is associated with accelerated muscle atrophy and increased erythrocyte glutathione turnover during 5 wk of bed rest
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DOI：
10.1093/ajcn/88.4.950
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发表时间：
2008-10-01
影响因子：
7.1
通讯作者：
Narici, Marco V.
中科院分区：
文献类型：
--
作者：
Biolo, Gianni;Agostini, Francesco;Narici, Marco V.
背景资料：身体不活动往往与积极的能量平衡和fat gain.Objective：我们的目的是评估是否能量摄入量超过要求激活全身炎症和抗氧化防御和加速肌肉萎缩inactivity.Design：19名健康男性志愿者进行了研究之前和结束时5周的卧床休息。允许受试者自发适应降低的能量需求（研究A，n = 10）或提供活动匹配的饮食（研究B，n = 9）。根据不活动引起的脂肪量变化的中位数，确定能量平衡较高（HEB）或较低（LEB）的组（Delta FM，通过生物电阻抗分析评估）。（n = 19;中值Δ FM：1.4公斤），卧床休息介导的去脂体重减少（生物电阻抗分析）和股外侧肌厚度（超声成像）显著大于在HEB（AB）（分别为-3.8 +/-0.4 kg和-0.32 +/-0.04 cm）中，与在LEB（AB）（分别为-2.3 +/-0.5 kg和-0.09 +/-0.04 cm）受试者相比（P < 0.03）。在研究A中（中位Delta FM：1.8 kg），HEB A受试者中卧床休息介导的血浆瘦素、C反应蛋白和髓过氧化物酶升高幅度大于LEB A受试者（P < 0.04）。卧床引起红细胞谷胱甘肽合成速率的变化（L-[3，3-（2）H（2）]半胱氨酸掺入）（P = 0.03）HEB A（从70 +/- 19至164 +/- 29%/ d），比LEB（A）（从103 +/- 23到84 +/- 27%/d）受试者。结论：不活动期间的正能量平衡与更大的肌肉萎缩以及全身炎症和抗氧化防御的激活相关。优化热量摄入可能是一个有用的策略，以减轻肌肉损失期间的慢性不活动。
Background: Physical inactivity is often associated with positive energy balance and fat gain.Objective: We aimed to assess whether energy intake in excess of requirement activates systemic inflammation and antioxidant defenses and accelerates muscle atrophy induced by inactivity.Design: Nineteen healthy male volunteers were studied before and at the end of 5 wk of bed rest. Subjects were allowed to spontaneously adapt to decreased energy requirement (study A, n = 10) or were provided with an activity-matched diet (study B, n = 9). Groups with higher (HEB) or lower (LEB) energy balance were identified according to median values of inactivity-induced changes in fat mass (Delta FM, assessed by bioelectrical impedance analysis).Results: In pooled subjects (n = 19; median Delta FM: 1.4 kg), bed rest-mediated decreases in fat-free mass (bioelectrical impedance analysis) and vastus lateralis thickness (ultrasound imaging) were significantly greater (P < 0.03) in HEB(AB) (-3.8 +/- 0.4 kg and -0.32 +/- 0.04 cm, respectively) than in LEB(AB) (-2.3 +/- 0.5 kg and -0.09 +/- 0.04 cm, respectively) subjects. In study A(median Delta FM: 1.8 kg), bed rest-mediated increases in plasma leptin, C-reactive protein, and myeloperoxidase were greater (P < 0.04) in HEB A than in LEB A subjects. Bed rest-mediated changes of glutathione synthesis rate in eythrocytes (L-[3,3-(2)H(2)] cysteine incorporation) were greater (P = 0.03) in HEB A (from 70 +/- 19 to 164 +/- 29%/ d) than in LEB(A) (from 103 +/- 23 to 84 +/- 27%/d) subjects.Conclusions: Positive energy balance during inactivity is associated with greater muscle atrophy and with activation of systemic inflammation and of antioxidant defenses. Optimizing caloric intake may be a useful strategy for mitigating muscle loss during period of chronic inactivity.