0～15岁儿童血中氨基酸浓度变化调查

Changes of blood amino acids in children aged 0 - 15 years

目的调查0～15岁儿童血中氨基酸浓度的变化情况，为评价氨基酸营养状态和诊断氨基酸代谢病提供帮助。方法以1900名0—15岁儿童为研究对象，采用非衍生法前处理滤纸血片，串联质谱测定11种氨基酸浓度。结果血缬氨酸、亮氨酸、苯丙氨酸、甘氨酸、酪氨酸、脯氨酸、鸟氨酸和丙氨酸浓度在出生后开始逐渐降低，4～6个月时最低，此后逐渐升高，7个月-1岁后相对稳定；血蛋氨酸、精氨酸浓度在出生后最低，1—3个月时最高，此后开始下降，4～6个月后水平稳定；血丙氨酸和甘氨酸浓度分别在9岁女孩和11岁男孩中达到第2高峰。鸟氨酸／精氨酸、瓜氨酸／精氨酸和鸟氨酸／瓜氨酸的比值出生时较高，此后逐渐降低，3个月-1岁后维持稳定；苯丙氨酸／酪氨酸比值在出生时最低，以后逐渐升高，6个月～1岁后维持稳定。7个月～15岁年龄组的血氨基酸水平与1d～1个月年龄组和／或2～6个月年龄组间差异均有统计学意义（P〈0．05或P〈0．01）。1d～1个月年龄组和全年龄组女性氨基酸浓度均明显高于男性（P〈0．05或P〈0．01）。结论1岁以内血中氨基酸浓度和构成比变化较大，在评价氨基酸营养状态和诊断氨基酸代谢病时要考虑年龄因素。

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, praline, 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 omithin 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-I 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.