The Body Cell Mass and Its Supporting Environment. Body Composition in Health and Disease (review)

Abstract

The Body CellMass andIts Supporting Environment. Body Composition in Health andDisease. By Francis D. Moore, Knud H. Olesen,James D. McMurrby, H. Victor Parker, Margaret R. Ball, and Caryl Magnus Boyden. Philadelphia-London: W. B. Saunders Company, 1963. Pp. xxv+535. $23.00. Theprinciple ofisotopedilutionhas providedakeyto exploration ofhumanbodycomposition and its changes with trauma or disease. Dr. Moore and his group have been leaders in the application ofmethods based on this principle and in the painstaking assembly ofdata from normal subjects and patients. This monograph summarizes and discusses in detail the last nine years of their work. Each study included measurement ofthe dilution of Na24 (total exchangeable sodium), K42 (total exchangeable potassium), Br82 (total exchangeable chloride and extracellular water), deuterium or tritium oxide (total body water), and Ci^-tagged red cells (red cell volume). Plasma volume was determined with the dye T-i824, and body weight was measured. Complete studies are presented from 34 normal adults, with partial data from many others, and similar observations are described in several patients with each of the following: chronic wasting disease, acute trauma, burns, hemorrhage, hypo- and hypernatremia, heart disease, renal or hepatic failure, and obesity. The book begins with a discussion ofthe theoretical basis ofthe methods used; actual procedures aredescribed in detail in appendices. The degree ofvalidation orreproducibility and some limitations ofeach technique are indicated. Statistical methods are described in a separate chapter. By the use ofresins for ion separation, the dose ofradioactivity for each study has recently been lowered to approximately 0.30 rad, the amount of blood drawn has been reduced to 90 ml., and the samples are all taken within a period of27 hours. Exchange equilibrium ofdeuterium and oftagged red cells was established by two separate determinations in each study. Longer periods ofdeuterium equilibration were used forpatients with edema or ascites. The bromide volume ofdistributionwas measured once at 14 hours; potassium and sodium were sampled once at 24 hours. From these basic measurements many derivations and ratios were calculated. For instance , total body fat was estimated from total body water by use ofthe factor .732 for water content ofthe fàt-free body. Justification for use ofthis factor is fully discussed. Skeletal weight, which was taken onthe basis ofthe scanty data available as 10.3 per cent offat-free body weight prior to illness, was related to the ratio of total exchangeable potassium over fat-free solids. (Fat-free solids equal body weight minus body water and fat; fatwas estimatedfrom body water as indicated previously.) This ratio was chosen because of the low potassium content of bone. It was assumed that the skeleton lost no weight during wasting illness. These examples may serve to suggest, but are not adequate fully to represent, the manner oftreatment ofthe data and the difficulties that were confronted in trying to extend the significance ofprimary measurements. Ofcentral importance in the opinion ofthe authors is the derivation ofthe body cell mass, "the homogeneous energy-exchanging, work-performing moiety of body tissue measurable by the total exchangeable potassium." The body cell mass is smaller and more homogeneous than the lean body mass (or fàt-free body), which includes the skeleton and 125 other extracellular supporting structures, as well as extracellular water. The latter concept, Dr. Moore suggests, is too heterogeneous to be offurther use, and the body cell mass is "the idealreference point for studies ofphysical fitness, ofthe fate ofthe cellular engine in disease, and ofthe anthropometric correlations ofenergy exchange." This book is perhaps most valuable for the amount of newly obtained data which it contains and for the clarity and completeness with which these are presented. Measurements , derived values, andratios are listedseparately foreachpatient studied, and reference standards from the appropriate subgroups of normals are included for comparison. Standards are given both in terms of observed body weight and weight prior to illness or, where appropriate, observed total body water. There are illuminating discussions, based largely on the authors' data, ofsome familiar clinical problems, e.g., loss ofcellular tissue with wasting disease, accumulation ofextracellular fluid after trauma, rate oftranscapillary refilling of blood volume after hemorrhage, rate ofplasma dispersal after infusion , distortions of osmolality with tube feeding or overhydration, retention of salt and water in heart disease...