Body composition of premature infants: relation to nutrition

Abstract

Five comparable groups of premature infants, each consisting of six infants were studied. On the 6th and 28th days of life, body weight, total body water, and extracellular water were determined and intracellular water and dry body weight were calculated. During the 21-day interval, the infants were fed isocalorically at a rate of 120 kcal/kg per day one of the following milks: human milk, SMA S-26, Similac 0.67, Alacta. Analyses of variance were performed on the 6-day data. Analyses of covariance were performed on the 28-day with the 6-day data taken as the covariate. Differences between pairs of treatment means were tested. A stepwise, multiple linear regression and correlation program was employed to determine the influence of milk constituents on body composition. It was found that: 1) Diet had an influence on body composition. 2) There were no statistically significant differences in the final absolute dry weights. 3) There were statistically significant differences in the amounts of final total body water. 4) There were differences in the distribution of body water into the intra- and extracellular compartments. 5) Electrolytes, their relative amounts in the milks, and the ratio of electrolytes (namely potassium) to protein were found to influence body composition. The results and their interpretation are discussed.