Urban Public Health and Nutrition Program, Hunter College, City University of New York, New York, USA.
Flushing Hospital Medical Center, Flushing, New York, USA.
J Med Food. 2022 Feb;25(2):117-120. doi: 10.1089/jmf.2021.0094. Epub 2021 Oct 29.
Sarcopenia and muscle wasting have many negative impacts on health and well-being. Evidence suggests that high rates of COVID-19 hospitalizations and lockdown conditions will lead to a marked increase in musculoskeletal disorders associated with sarcopenia in older adults. The molecular etiology of sarcopenia is complex, but physical inactivity, poor diet, and age diminished ability to stimulate muscle protein synthesis (MPS) remain important drivers. A body of evidence shows that, acting through the highly conserved nutrient sensor pathway mTORc1, the branch chain amino acid leucine can trigger and enhance MPS in older adults, and thus has a role in the medical management of sarcopenia. Whey protein-enriched enteral supplements are a low cost, easily accessible source of highly bioavailable leucine used clinically in older adults for preservation of lean body mass in long-term care setting. Therefore, given the evidence of leucine's ability to stimulate MPS in older adults, we argue that meal supplementation with whey-enriched enteral products, which can provide the 3-5 g of leucine necessary to trigger MPS in older adults, should be given serious consideration by medical and nutrition professionals to potentially mitigate muscle wasting and sarcopenia risk associated with prolonged COVID-19 lockdown measures.
肌肉减少症和肌肉消耗对健康和幸福感有许多负面影响。有证据表明，高比例的 COVID-19 住院率和封锁条件将导致与老年人肌肉减少症相关的肌肉骨骼疾病显著增加。肌肉减少症的分子病因复杂，但身体活动减少、饮食不良和年龄导致刺激肌肉蛋白质合成（MPS）的能力下降仍然是重要的驱动因素。大量证据表明，支链氨基酸亮氨酸通过高度保守的营养传感器途径 mTORc1 发挥作用，可以触发和增强老年人的 MPS，因此在肌肉减少症的医学管理中具有作用。富含乳清蛋白的肠内补充剂是一种低成本、易于获得的高生物利用度亮氨酸来源，在老年人中长期护理环境中用于保留瘦体重。因此，鉴于亮氨酸刺激老年人 MPS 的能力的证据，我们认为，通过膳食补充富含乳清蛋白的肠内产品，为老年人提供 3-5g 的亮氨酸以触发 MPS，这应该引起医学和营养专业人员的认真考虑，以潜在减轻与 COVID-19 长期封锁措施相关的肌肉消耗和肌肉减少症风险。
