Plasma amino acid patterns, one and two hours after continuous naso-gastric alimentation of low birth weight infants fed two types of milk during the first month of life.
Plasma amino acid concentrations were determined in the morning, 1 and 2 h after discontinuing any naso-gastric feeding on the 3rd, 5th, 15th and 30th days of life, in order to establish their course according to the moment of sampling and to the type of diet given. Two types of conventional naso-gastric feeding were given in 12 infants with a birth weight of 1,500 g or less. The diets supplied either 1.2 g proteins/100 ml (pooled human milk) or 1.8 g proteins/100 ml ("humanized formula' with an albumin/casein ratio of 60/40) from the 3rd h to the 30th day of life. No statistically significant difference appeared between the amino acid concentrations 1 and 2h after discontinuation of naso-gastric alimentation on the 3rd, 5th and 15th days whichever milk was used, but a significant difference appeared for two amino acids on day 30 (phenylalanine and lysine) when fed the humanized formula. It is concluded that caution might be necessary when interpreting amino acid results: the moment of sampling induced a statistically significant difference on day 30 of life only for phenylalanine and lysine in children fed on a "humanized formula'.