Chaput J P, Lord C, Cloutier M, Aubertin Leheudre M, Goulet E D B, Rousseau S, Khalil A, Dionne I J
Research Centre on Aging, 1036 Belvedere Sud. Sherbrooke, Quebec, Canada.
J Nutr Health Aging. 2007 Jul-Aug;11(4):363-9.
The effect of nutritional intake on sarcopenia has been mostly examined in class II sarcopenia, i.e. when muscle mass has sufficiently decreased to induce a loss in physical capacity. Although this provides important information regarding the treatment of sarcopenia, it may not help highlight mechanisms involved at the very beginning of its development.
We hypothesized that class I sarcopenia is associated with differences in antioxidant intakes (vitamins A, C, E and selenium) and status in healthy, older white men and women when physical activity and protein intake are taken into account.
Fat-free mass and total appendicular skeletal muscle mass was determined by dual-energy X-ray absorptiometry in 50 healthy, older white men (n = 16) and women (n = 34) aged 60-75 yrs. Physical activity energy expenditure (PAEE) was determined using a Caltrac accelerometer over a 3-d period. Dietary protein and antioxidant intakes were estimated from a 3-d food record and serum total antioxidant activity (TAA) was measured by a ferrylmyoglobin- ABTS assay.
The prevalence of class I sarcopenia was 23.5 % in women and 25.0 % in men; 12 participants were thus considered sarcopenic (4 men and 8 women) and 38 participants were considered nonsarcopenic (12 men and 26 women). Our results showed that PAEE, serum albumin concentrations, TAA, and the four antioxidants intake levels were similar between groups. On the other hand, our results showed that total protein intake was significantly higher (P < 0.01) in the non-sarcopenic group than in the sarcopenic group. Also, the number of Recommended Dietary Allowances (RDAs) reached for the antioxidant nutrients and protein intakes by the non-sarcopenic group was significantly higher (P < 0.01) than in the sarcopenic group.
Although there were no significant differences between the sarcopenic and the non-sarcopenic group when antioxidant intakes were considered individually, we observed that the number of RDAs reached for antioxidant micronutrients and protein in healthy, older white men and women was lower in sarcopenic than nonsarcopenic individuals. Our results also suggest that a higher total dietary protein intake is associated with the preservation of muscle mass loss although both groups displayed values above actual RDAs. Obviously, prospective studies are needed to determine the minimum amount of protein in the diet needed to prevent class I sarcopenia and to examine the utility of antioxidant intake to combat the age-related loss in skeletal muscle mass.
营养摄入对肌肉减少症的影响大多是在II级肌肉减少症中进行研究的，即当肌肉量已充分减少以导致身体能力下降时。虽然这为肌肉减少症的治疗提供了重要信息，但它可能无助于突出其发展初期所涉及的机制。
我们假设，在考虑身体活动和蛋白质摄入的情况下，I级肌肉减少症与健康老年白人男性和女性的抗氧化剂摄入量（维生素A、C、E和硒）及状态差异有关。
通过双能X线吸收法测定了50名年龄在60 - 75岁的健康老年白人男性（n = 16）和女性（n = 34）的去脂体重和全身骨骼肌总量。使用Caltrac加速度计在3天内测定身体活动能量消耗（PAEE）。通过3天的饮食记录估算膳食蛋白质和抗氧化剂摄入量，并通过高铁肌红蛋白 - ABTS法测量血清总抗氧化活性（TAA）。
I级肌肉减少症的患病率在女性中为23.5%，在男性中为25.0%；因此，12名参与者被认为患有肌肉减少症（4名男性和8名女性），38名参与者被认为没有肌肉减少症（12名男性和26名女性）。我们的结果表明，两组之间的PAEE、血清白蛋白浓度、TAA以及四种抗氧化剂的摄入水平相似。另一方面，我们的结果表明，非肌肉减少症组的总蛋白质摄入量显著高于肌肉减少症组（P < 0.01）。此外，非肌肉减少症组达到的抗氧化营养素和蛋白质摄入量的推荐膳食摄入量（RDA）数量显著高于肌肉减少症组（P < 0.01）。
虽然单独考虑抗氧化剂摄入量时，肌肉减少症组和非肌肉减少症组之间没有显著差异，但我们观察到，健康老年白人男性和女性中，肌肉减少症患者达到的抗氧化微量营养素和蛋白质的RDA数量低于非肌肉减少症患者。我们的结果还表明，较高的膳食总蛋白质摄入量与维持肌肉量减少有关，尽管两组的数值均高于实际RDA。显然，需要进行前瞻性研究来确定预防I级肌肉减少症所需的饮食中蛋白质的最低量，并研究抗氧化剂摄入对对抗与年龄相关的骨骼肌量损失的效用。
