Table_1_Impact of exercise and leucine-enriched protein supplementation on physical function, body composition, and inflammation in pre-frail older adults: a quasi-experimental study.DOCX

BackgroundExercise and a protein-enriched diet are essential for muscle protein synthesis, cellular growth, mitochondrial function, and immune function. The U.S. Food and Nutrition Board's current guideline on recommended dietary allowance for protein in older adults is 0.8 g/kg per day, which may not be sufficient in vulnerable pre-frail older adults.
AimsThis study aimed to evaluate the impact of leucine-enriched protein supplementation with or without exercise over 3 months in pre-frail older adults who consumed ≤1 g/kg/day of protein on improving (i) physical function, (ii) body composition measures, and (iii) inflammatory biomarkers such as interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α).
MethodsA non-randomized cluster quasi-experimental study guided by the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist of 178 pre-frail older adults [112 control, 44 nutrition (Nu), and 22 in the nutrition with exercise (Nu+Ex) group] comparing the effect of Nu+Ex and Nu on physical function, body composition, and inflammation. At 0, 3, and 6 months, questionnaires on demographics, depression, perceived health, and cognition were administered. Physical function assessment (short physical performance battery [SPPB] test, gait speed, handgrip strength, 5× sit-to-stand [STS]) was conducted, and body composition analysis was performed using a bioelectrical impedance analysis machine. IL-6 and TNF-α were measured at 0 and 3 months.
ResultsAt 3 months, there were significant improvements in gait speed, 5× STS, SPPB scores, depression, perceived health, fat-free mass, and appendicular skeletal muscle mass indices in the Nu+Ex group. Both Nu+Ex and Nu groups had improvements in body cell mass and reductions in IL-6 and TNF-α. The improvements were not sustained after 6 months.
ConclusionOur study results need to be validated in future longitudinal randomized studies with a larger sample size focusing on populations at risk.

背景 运动与高蛋白饮食对于肌肉蛋白质合成、细胞生长、线粒体功能以及免疫功能均至关重要。美国食品与营养委员会（U.S. Food and Nutrition Board）目前针对老年人的蛋白质推荐膳食摄入量标准为每日0.8g/kg，但该标准对于体弱衰弱前期的老年群体可能并不充足。
研究目的 本研究旨在评估，对于每日蛋白质摄入量≤1g/kg的衰弱前期老年人，为期3个月的富含亮氨酸的蛋白质补充剂联合或不联合运动，对以下指标的改善效果：(i) 躯体功能；(ii) 身体成分指标；(iii) 白细胞介素-6（interleukin-6, IL-6）、肿瘤坏死因子-α（tumor necrosis factor alpha, TNF-α）等炎症生物标志物。
研究方法 本研究为非随机整群类实验研究，遵循《流行病学观察性研究报告规范》（Strengthening the Reporting of Observational Studies in Epidemiology, STROBE）清单进行设计，共纳入178名衰弱前期老年人，分为3组：对照组112人、营养干预组（nutrition, Nu）44人、运动联合营养干预组（nutrition with exercise, Nu+Ex）22人，旨在对比Nu+Ex与Nu方案对躯体功能、身体成分及炎症水平的影响。分别于基线（0个月）、3个月、6个月时，收集人口学信息、抑郁情况、自我感知健康状况及认知功能相关问卷数据。躯体功能评估包括短体能电池（short physical performance battery, SPPB）测试、步速、握力及5次坐立试验（5× sit-to-stand, STS）；身体成分分析采用生物电阻抗分析仪完成。分别于0个月和3个月时检测血清IL-6与TNF-α水平。
研究结果 干预3个月后，Nu+Ex组的步速、5次坐立试验成绩、SPPB评分、抑郁状态、自我感知健康状况、无脂体重及四肢骨骼肌质量指数均得到显著改善。Nu+Ex组与Nu组的体细胞质量均有所提升，且IL-6、TNF-α水平均出现下降。上述改善效果在6个月时未得到持续维持。
研究结论 本研究结果需在未来更大样本量的纵向随机对照研究中针对高危人群进行验证。