Schneider Stephane M, Al-Jaouni Rima, Pivot Xavier, Braulio Valeria B, Rampal Patrick, Hebuterne Xavier
Gastroenterology and Nutrition Department, Archet University Hospital, University of Nice Sophia-Antipolis, France.
Clin Nutr. 2002 Dec;21(6):499-504. doi: 10.1054/clnu.2002.0584.
BACKGROUND & AIMS: Sarcopenia is a common feature in the healthy elderly. However, little is known on age-related modifications of body composition in malnourished patients. The aims of this cross-sectional study were to evaluate the effects of aging per se on body composition and resting energy expenditure (REE) in malnourished patients.
Ninety-seven non-stressed patients referred for chronic malnutrition (C-reactive protein <5 mg/l) were separated into two groups: middle-aged (26 female, 19 male, 48+/-15 yr), and elderly (26 female, 26 male, 79+/-6 yr). Body composition was assessed by bioelectrical impedance analysis and REE by indirect calorimetry.
In middle-aged patients, body composition remained stable between moderate (body-mass index [BMI; in kg/m(2)] 16-18.5) and severe (BMI < 16) malnutrition, with similar values of fat-free mass (FFM), body cell mass (BCM) and fat mass (FM) as percentages of body weight, whereas in elderly patients malnutrition occurred at the expense of FFM and BCM, with unchanged FM absolute values. REE/FFM values remained stable in middle-aged patients at every stage of malnutrition, whereas they increased in elderly patients along with their degree of malnutrition. In multivariate analysis, both body composition and REE/FFM were influenced by sex, age, BMI and mid-arm circumference.
Compared to younger patients, weight loss in the elderly leads to cachexia, with a preferential loss of FFM and BCM that may participate in the more severe outcomes observed in these patients. They also show elevated REE/FFM values that induce higher energy needs.
肌肉减少症是健康老年人的常见特征。然而，对于营养不良患者身体成分的年龄相关变化知之甚少。本横断面研究的目的是评估衰老本身对营养不良患者身体成分和静息能量消耗（REE）的影响。
97名因慢性营养不良（C反应蛋白<5mg/L）前来就诊的无应激患者被分为两组：中年组（26名女性，19名男性，48±15岁）和老年组（26名女性，26名男性，79±6岁）。通过生物电阻抗分析评估身体成分，通过间接测热法评估REE。
在中年患者中，中度（体重指数[BMI；单位：kg/m²]16 - 18.5）和重度（BMI<16）营养不良之间身体成分保持稳定，无脂肪量（FFM）、身体细胞量（BCM）和脂肪量（FM）占体重的百分比相似，而在老年患者中，营养不良以FFM和BCM为代价发生，FM绝对值不变。在中年患者中，营养不良各阶段REE/FFM值保持稳定，而在老年患者中，其随营养不良程度增加。多变量分析中，身体成分和REE/FFM均受性别、年龄、BMI和上臂围影响。
与年轻患者相比，老年人体重减轻会导致恶病质，优先损失FFM和BCM，这可能是这些患者出现更严重后果的原因。他们还表现出升高的REE/FFM值，导致更高的能量需求。
