Effect of vitamin C and E supplementation and elastic-band resistance training on muscle mass, strength, physical performance, oxidative stress, and inflammation in older women with sarcopenia: A 12-week randomized, double-blind, placebo-controlled trial

Purpose: This study aimed to explore the effects of 12 weeks of elastic-band resistance training (RT) with vitamin C and E supplementation on muscle mass, strength, physical performance, and blood parameters of oxidative stress (OS) and inflammation in older women with sarcopenia.
Methods: Seventy participants (60 to 75 years) were randomized to an antioxidant supplementation group (AS; 1000 mg/d vitamin C and 335 mg/d vitamin E; n = 35) or a placebo group (PLA; n = 35) following the same RT program (three sessions per week). Muscle mass (measured by dual-energy X-ray absorptiometry), strength (measured by handgrip strength and knee extension strength), physical performance (5-Repetition Chair Stand Test, Timed Up and Go Test, and 6-meter Gait Speed), OS-related indices (reduced [GSH] and oxidized [GSSG] glutathione, GSH/GSSG ratio, malondialdehyde [MDA], and protein carbonyl [PCO]), and pro-inflammatory factors (interleukin-6 [IL-6] and tumor necrosis factor-alpha [TNF-α]) were evaluated at baseline and after the 12-week intervention.
Results: RT improved muscle mass, muscle strength and physical performance. The AS group had higher increases in arm lean mass (P = 0.003; d = 0.74), SMI (p = 0.004; d = 0.71), handgrip strength (P = 0.047; d = 0.51), and knee extension strength (P < 0.001; d = 0.89) than the PLA group but showed no additional improvement in all physical performance tests. In terms of blood parameters, the PLA group had increased serum levels of GSSG, MDA, and PCO and decreased GSH/GSSG ratio. By contrast, the AS group had increased GSH (P < 0.001; d = 1.52) and GSH/GSSG ratio (P < 0.001; d = 1.52) and reduced GSSG (P < 0.001; d = 0.96) and MDA (P < 0.001; d = 1.65). The levels of IL-6 and TNF-α significantly decreased in the PLA and AS groups, and serum IL-6 level was lower in the AS group than in the PLA group (P < 0.001; d = 1.16).
Conclusions: Vitamin C and E supplementation combined with RT may enhance neuromuscular adaptations (i.e., muscle mass and strength) in older women with sarcopenia by improving OS and inflammation levels post-training.

研究目的：本研究旨在探讨为期12周的弹力带抗阻训练（resistance training, RT）联合维生素C、E补充剂对肌少症老年女性的肌肉质量、肌力、身体机能，以及氧化应激（oxidative stress, OS）与炎症相关血液指标的影响。
研究方法：招募70名年龄介于60至75岁的受试者，随机分为抗氧化补充组（AS；每日补充1000 mg维生素C与335 mg维生素E；n=35）与安慰剂组（PLA；n=35），两组均遵循相同的抗阻训练方案，每周训练3次。分别于基线及12周干预结束后，对以下指标进行检测：肌肉质量（采用双能X线吸收法测定）、肌力（采用握力与膝关节伸肌力量测定）、身体机能（5次坐站试验、计时起立行走试验以及6米步行速度）、氧化应激相关指标（还原型谷胱甘肽[GSH]、氧化型谷胱甘肽[GSSG]、GSH/GSSG比值、丙二醛[MDA]与蛋白质羰基[PCO]），以及促炎因子（白细胞介素-6[IL-6]与肿瘤坏死因子-α[TNF-α]）。
研究结果：抗阻训练可提升肌肉质量、肌力与身体机能。相较于安慰剂组，抗氧化补充组的上肢瘦体重（P=0.003; d=0.74）、骨骼肌质量指数（SMI）（P=0.004; d=0.71）、握力（P=0.047; d=0.51）与膝关节伸肌力量（P<0.001; d=0.89）提升幅度更为显著，但在各项身体机能测试中未展现额外改善。血液指标方面，安慰剂组的血清GSSG、MDA与PCO水平升高，而GSH/GSSG比值降低；与之相反，抗氧化补充组的GSH水平（P<0.001; d=1.52）与GSH/GSSG比值（P<0.001; d=1.52）升高，GSSG（P<0.001; d=0.96）与MDA（P<0.001; d=1.65）水平降低。两组受试者的IL-6与TNF-α水平均显著下降，且抗氧化补充组的血清IL-6水平低于安慰剂组（P<0.001; d=1.16）。
研究结论：对于肌少症老年女性，补充维生素C与E联合抗阻训练，可通过改善训练后机体氧化应激与炎症水平，增强神经肌肉适应性（即肌肉质量与肌力提升）。