Lord C, Chaput J P, Aubertin-Leheudre M, Labonté M, Dionne I J
Research Centre on Aging, Geriatric Institute of Sherbrooke University, Faculty of Physical Education and Sports, Québec, Canada.
J Nutr Health Aging. 2007 Sep-Oct;11(5):383-7.
Aging is associated with reductions in muscle mass and strength, so-called sarcopenia, and is generally characterized using muscle mass index (MMI = FFM (kg)/height (m)2). It is believed that adequate nutrition especially regarding protein intake, can delay this progression and enhance the quality of life of elders.
We examined whether the predominant source of protein consumed (animal or vegetal) by older women was associated with MMI.
Thirty-eight healthy, normal weight, sedentary women, aged between 57-75 years (mean age: 66 +/- 5 years old), and taking no medication that could influence metabolism were recruited. Body composition was measured by dual-energy X-ray absorptiometry; muscle protein content was measured by the use of creatinine excretion. Physical activity metabolism was obtained by the use of accelerometry, and indirect calorimetry. Finally, protein intake was measured with a 3-day dietary record.
Significant correlations were observed between MMI and body mass index, fat-free mass, muscle protein content, total protein intake, animal protein intake, fat mass, visceral fat and daily energy expenditure. However, a stepwise regression analysis showed animal protein intake to be the only independent predictor of MMI (r2=0.19; p=0.008).
Our results suggest that protein intake, especially from animal sources, may be associated with a better preservation of MMI. However, more research is needed to confirm our results.
衰老与肌肉质量和力量的下降相关，即所谓的肌肉减少症，通常使用肌肉质量指数（MMI = 去脂体重（kg）/身高（m）²）来表征。人们认为充足的营养，特别是蛋白质摄入，可以延缓这一进程并提高老年人的生活质量。
我们研究了老年女性摄入蛋白质的主要来源（动物蛋白或植物蛋白）是否与肌肉质量指数相关。
招募了38名健康、体重正常、久坐不动的女性，年龄在57 - 75岁之间（平均年龄：66 ± 5岁），且未服用可能影响新陈代谢的药物。通过双能X线吸收法测量身体成分；通过肌酐排泄量测量肌肉蛋白质含量。通过加速度计和间接量热法获得身体活动代谢情况。最后，通过3天饮食记录测量蛋白质摄入量。
观察到肌肉质量指数与体重指数、去脂体重、肌肉蛋白质含量、总蛋白质摄入量、动物蛋白摄入量、脂肪量、内脏脂肪和每日能量消耗之间存在显著相关性。然而，逐步回归分析表明动物蛋白摄入量是肌肉质量指数的唯一独立预测因素（r² = 0.19；p = 0.008）。
我们的结果表明，蛋白质摄入，尤其是动物来源的蛋白质摄入，可能与更好地维持肌肉质量指数有关。然而，需要更多研究来证实我们的结果。
