Fuchs Cas J, Hermans Wesley J H, Nyakayiru Jean, Weijzen Michelle E G, Smeets Joey S J, Aussieker Thorben, Senden Joan M, Wodzig Will K H W, Snijders Tim, Verdijk Lex B, van Loon Luc J C
Department of Human Biology, Faculty of Health, Medicine and Life Sciences, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, The Netherlands.
Central Diagnostic Laboratory, Maastricht University Medical Centre+, Maastricht, The Netherlands.
J Physiol. 2024 Feb 27. doi: 10.1113/JP286065.
We measured the impact of blood flow restriction on muscle protein synthesis rates, muscle mass and strength during 2 weeks of strict bed rest. Twelve healthy, male adults (age: 24 ± 3 years, body mass index: 23.7 ± 3.1 kg/m ) were subjected to 14 days of strict bed rest with unilateral blood flow restriction performed three times daily in three 5 min cycles (200 mmHg). Participants consumed deuterium oxide and we collected blood and saliva samples throughout 2 weeks of bed rest. Before and immediately after bed rest, lean body mass (dual-energy X-ray absorptiometry scan) and thigh muscle volume (magnetic resonance imaging scan) were assessed in both the blood flow restricted (BFR) and control (CON) leg. Muscle biopsies were collected and unilateral muscle strength (one-repetition maximum; 1RM) was assessed for both legs before and after the bed rest period. Bed rest resulted in 1.8 ± 1.0 kg lean body mass loss (P < 0.001). Thigh muscle volume declined from 7.1 ± 1.1 to 6.7 ± 1.0 L in CON and from 7.0 ± 1.1 to 6.7 ± 1.0 L in BFR (P < 0.001), with no differences between treatments (P = 0.497). In addition, 1RM leg extension strength decreased from 60.2 ± 10.6 to 54.8 ± 10.9 kg in CON and from 59.2 ± 12.1 to 52.9 ± 12.0 kg in BFR (P = 0.014), with no differences between treatments (P = 0.594). Muscle protein synthesis rates during bed rest did not differ between the BFR and CON leg (1.11 ± 0.12 vs. 1.08 ± 0.13%/day, respectively; P = 0.302). Two weeks of bed rest substantially reduces skeletal muscle mass and strength. Blood flow restriction during bed rest does not modulate daily muscle protein synthesis rates and does not preserve muscle mass or strength. KEY POINTS: Bed rest, often necessary for recovery from illness or injury, leads to the loss of muscle mass and strength. It has been postulated that blood flow restriction may attenuate the loss of muscle mass and strength during bed rest. We investigated the effect of blood flow restriction on muscle protein synthesis rates, muscle mass and strength during 2 weeks of strict bed rest. Blood flow restriction applied during bed rest does not modulate daily muscle protein synthesis rates and does not preserve muscle mass or strength. Blood flow restriction is not effective in preventing muscle atrophy during a prolonged period of bed rest.
我们测量了在为期2周的严格卧床休息期间，血流限制对肌肉蛋白质合成速率、肌肉质量和力量的影响。12名健康男性成年人（年龄：24±3岁，体重指数：23.7±3.1kg/m²）接受了14天的严格卧床休息，单侧血流限制每天进行3次，每次5分钟循环（200mmHg）。参与者摄入氧化氘，我们在整个2周的卧床休息期间采集血液和唾液样本。在卧床休息前后，通过双能X线吸收法扫描评估血流限制（BFR）腿和对照（CON）腿的瘦体重，通过磁共振成像扫描评估大腿肌肉体积。采集肌肉活检样本，并在卧床休息期前后评估双腿的单侧肌肉力量（一次重复最大值；1RM）。卧床休息导致瘦体重减少1.8±1.0kg（P<0.001）。CON组大腿肌肉体积从7.1±1.1L降至6.7±1.0L，BFR组从7.0±1.1L降至6.7±1.0L（P<0.001），各治疗组之间无差异（P=0.497）。此外，CON组腿伸展1RM力量从60.2±10.6kg降至54.8±10.9kg，BFR组从59.2±12.1kg降至52.9±12.0kg（P=0.014），各治疗组之间无差异（P=0.594）。卧床休息期间BFR腿和CON腿的肌肉蛋白质合成速率无差异（分别为1.11±0.12%/天和1.08±0.13%/天；P=0.302）。两周的卧床休息显著降低了骨骼肌质量和力量。卧床休息期间的血流限制不会调节每日肌肉蛋白质合成速率，也不会维持肌肉质量或力量。要点：卧床休息通常是疾病或损伤恢复所必需的，但会导致肌肉质量和力量的丧失。据推测，血流限制可能会减轻卧床休息期间肌肉质量和力量的丧失。我们研究了在为期2周的严格卧床休息期间，血流限制对肌肉蛋白质合成速率、肌肉质量和力量的影响。卧床休息期间应用的血流限制不会调节每日肌肉蛋白质合成速率，也不会维持肌肉质量或力量。血流限制在长时间卧床休息期间预防肌肉萎缩方面无效。
