619 RELATIONSHIPS BETWEEN TOTAL BODY WATER AND ANTHROPOMETRY IN YOUNG PERUVIAN CHILDREN

Abstract

Recent studies show that in preschool-aged children from poor marginal communities outside Lima, Peru, 90% are below the 50th %ile in height-for-age, while 68% are above the 50th %ile in weight-for-height. In order to describe body composition and develop equations to predict body composition, total body water (TBW) was measured on 134 Peruvian children by 18O dilution, together with 34 anthropometric variables. TBW as a % of body weight averaged 67.5 ± 8.1%, corresponding to an average % fat of 13.6 ± 10.6%. TBW as a % of body weight is higher (and % fat is lower) than the values for Fomon's American reference children. TBW was significantly (P < 0.05) correlated with 23 anthropometric variables. Height and weight were the most highly correlated with TBW, both with r = 0.92. Equations to predict TBW from height or weight were significantly different from those developed for normal American children by Mellits and Cheek. Stepwise multiple regression showed that height, weight, suprailiac skinfold, sitting height, chest circumference, and height-for-age %ile score could account for 90% of the variation in TBW values. Conclusions: 1) TBW as a % of body weight is higher and % fat is lower in these children than in American children of comparable height, weight, and age; 2) height and weight are the anthropometric variables most highly correlated with TBW; and 3) a multiple regression analysis based on easily determined anthropometric measures can account for 90% of the variation in TBW values in this population.