Department of Medicine/Physiology, University of Fribourg, Fribourg, Switzerland.
Int J Obes (Lond). 2010 Dec;34 Suppl 2:S4-17. doi: 10.1038/ijo.2010.234.
Dynamic changes in body weight have long been recognized as important indicators of risk for debilitating diseases. While weight loss or impaired growth can lead to muscle wastage, as well as to susceptibility to infections and organ dysfunctions, the development of excess fat predisposes to type 2 diabetes and cardiovascular diseases, with insulin resistance as a central feature of the disease entities of the metabolic syndrome. Although widely used as the phenotypic expression of adiposity in population and gene-search studies, body mass index (BMI), that is, weight/height(2) (H(2)), which was developed as an operational definition for classifying both obesity and malnutrition, has considerable limitations in delineating fat mass (FM) from fat-free mass (FFM), in particular at the individual level. After an examination of these limitations within the constraints of the BMI-FM% relationship, this paper reviews recent advances in concepts about health risks related to body composition phenotypes, which center upon (i) the partitioning of BMI into an FM index (FM/H(2)) and an FFM index (FFM/H(2)), (ii) the partitioning of FFM into organ mass and skeletal muscle mass, (iii) the anatomical partitioning of FM into hazardous fat and protective fat and (iv) the interplay between adipose tissue expandability and ectopic fat deposition within or around organs/tissues that constitute the lean body mass. These concepts about body composition phenotypes and health risks are reviewed in the light of race/ethnic variability in metabolic susceptibility to obesity and the metabolic syndrome.
体重的动态变化一直被认为是导致衰弱性疾病风险的重要指标。虽然体重减轻或生长受损会导致肌肉消耗，以及易感染和器官功能障碍，但脂肪过多的发展会导致 2 型糖尿病和心血管疾病，胰岛素抵抗是代谢综合征疾病实体的一个核心特征。尽管体重指数（BMI）作为人群和基因研究中肥胖的表型表达被广泛应用，即体重/身高的平方（H²），但它作为肥胖和营养不良分类的操作定义，在区分脂肪量（FM）和无脂肪量（FFM）方面存在很大的局限性，尤其是在个体层面。在 BMI-FM%关系的限制内对这些局限性进行检查后，本文回顾了与身体成分表型相关的健康风险概念的最新进展，这些概念主要围绕以下几个方面：（i）将 BMI 分为脂肪指数（FM/H²）和无脂肪指数（FFM/H²），（ii）将 FFM 分为器官质量和骨骼肌质量，（iii）将 FM 分为危险脂肪和保护脂肪，以及（iv）构成瘦体重的器官/组织内或周围的脂肪组织扩展性和异位脂肪沉积之间的相互作用。这些关于身体成分表型和健康风险的概念是根据种族/民族对肥胖和代谢综合征的代谢易感性的可变性来审查的。
