PLASMA AMINO-ACID AND PROTEIN CONCENTRATIONS IN INFANTS FED HUMAN-MILK OR A WHEY-PROTEIN HYDROLYSATE FORMULA DURING THE FIRST MONTH OF LIFE

The aim of the study was to compare growth parameters, biochemical ind ices of protein metabolism and plasma amino acid concentrations in inf ants fed either human milk (n = 12) or a whey protein hydrolysate form ula (n = 13) during the first month of life. Growth and gain in skin f old thickness were similar in both groups whereas serum protein concen tration was significantly decreased (57.4+/-3.9 versus 61.2+/-2.9 g/l) in the infants fed the whey hydrolysate formula. The discrepancies be tween the plasma amino acid pattern of the whey hydrolysate formula gr oup and that of the human milk group lessened during the first month. Nevertheless, at a mean age of 33 days the plasma threonine concentrat ion remained twice as high and the plasma tyrosine, phenylalanine and proline concentrations were significantly lower in the whey hydrolysat e formula group than in the human milk group. Thus, compared with brea st-fed infants, growth and most of the biological indices of protein m etabolism were satisfactory in infants fed during the first month of l ife on a whey protein hydrolysate formula. Nevertheless, the decrease in total plasma protein concentration needs to be confirmed in a large r cohort of infants. In addition, further research is necessary to inv estigate the possible ways of reducing the hyperthreoninemia and preve nting other plasma amino acid disturbances since it would be desirable to obtain plasma amino acid levels similar to those of breast-fed inf ants.