Changes of blood amino acids in children aged 0 - 15 years / 中华临床营养杂志

ABSTRACT

Objective To investigate the blood levels of amino acids in children aged 0-15 year, with an attempt to provide evidence for evaluating amino acid status and diagnosing metabolic diseases of amino acid.Methods The blood levels of eleven amino acids in 1900 children aged 0-15 years were determined by tandem mass spectrometry (MS/MS). Results The blood levels of leucine & isoleucine, valine, phenylalanine tyrosine,glycine, proline, ornithine, and alanine gradually decreased after birth, reaching the lowest levels at the ages of 4-6 months, and then gradually increased, reaching the normal range at the ages of 7 months-1 year. The blood levels of alanine and glycine reach the second peaks on the ages of 9 years in girls and on 11 years in boys. The blood levels of methionine and arginine were lowest in the first week of age, became highest in 1-3 months, decreased to the normal ranges after 4-6 months, and kept the level afterwards. The ratios between prosomatic amino acid and productive amino acid, between ornithine and arginine, between citrulline and arginine, and between ornithin and citrulline were highest in the first week of age and decreased to normal values after 3 to 12 months. The concentrations of amino acids in group of 7 months-15 years were significantly different from the group of 1 day-1 month and group of 2-6 months (P ＜0. 05 or P ＜0. 01 ). The concentrations of amino acids were significantly higher in females than in males in the group of 1 day-1 month and in all age groups (P ＜0. 05 or P ＜0. 01 ) . Conclusions The concentrations and profiles of amino acids change remarkably during the first year of age. Age should be carefully considered when evaluating the nutritional status of amino acid and diagnosing metabolic diseases of amino acids.