Bouillanne Olivier, Dupont-Belmont Claire, Hay Phasaro, Hamon-Vilcot Brigitte, Cynober Luc, Aussel Christian
Hôpital Emile-Roux, Assistance Publique-Hôpitaux de Paris, Limeil-Brévannes, France.
Am J Clin Nutr. 2009 Sep;90(3):505-10. doi: 10.3945/ajcn.2009.27819. Epub 2009 Jul 29.
It is well established that the combination of protein-energy malnutrition and low body mass index (BMI) increases the risk of death in elderly patients, but recent studies indicate that the risk of death may decrease with higher body weight. However, these studies did not perform direct, separate, and reliable measurements of fat and lean mass by using a reference technique.
Our objective was to evaluate the relation between body composition, based on the 4-compartment model, and morbidity and mortality in hospitalized elderly patients.
This prospective study enrolled 125 elderly patients evaluated at admission for body composition on the basis of BMI plus fat mass, lean mass, appendicular skeletal muscle mass, and body cell mass indexes (calculated as the ratio of the mass to the square of the height) measured by X-ray absorptiometry and bioelectrical impedance analysis. Outcomes were assessed 6 mo later by using a score system that takes into account complications (pressure ulcers and/or infections) and 6-mo mortality.
The fat mass index correlated positively (r = 0.19 and P = 0.023 adjusted for sex; r = 0.18 and P = 0.043 adjusted for sex, albuminemia, and C-reactive protein) with outcome score (1: death, 2: complications, 3: no complications). There was no significant correlation between outcome score and BMI, lean mass, appendicular skeletal muscle mass, and body cell mass indexes.
This study clearly indicates that the generally accepted rule that overweight is associated with morbidity and mortality does not apply to hospitalized elderly patients, for whom fat mass is associated with a decreased risk of adverse events.
蛋白质 - 能量营养不良与低体重指数（BMI）相结合会增加老年患者的死亡风险，这一点已得到充分证实，但最近的研究表明，体重增加可能会降低死亡风险。然而，这些研究并未使用参考技术对脂肪量和去脂体重进行直接、单独且可靠的测量。
我们的目的是评估基于四成分模型的身体组成与住院老年患者的发病率和死亡率之间的关系。
这项前瞻性研究纳入了125名老年患者，他们在入院时根据BMI加上通过双能X线吸收法和生物电阻抗分析测量的脂肪量、去脂体重、四肢骨骼肌量和身体细胞量指数（计算为质量与身高平方的比值）进行身体组成评估。6个月后，使用一个考虑并发症（压疮和/或感染）和6个月死亡率的评分系统评估结果。
脂肪量指数与结果评分（1：死亡，2：并发症，3：无并发症）呈正相关（经性别调整后r = 0.19，P = 0.023；经性别、白蛋白血症和C反应蛋白调整后r = 0.18，P = 0.043）。结果评分与BMI、去脂体重、四肢骨骼肌量和身体细胞量指数之间无显著相关性。
这项研究清楚地表明，超重与发病率和死亡率相关这一普遍接受的规则不适用于住院老年患者，对他们而言，脂肪量与不良事件风险降低相关。
