新生儿血游离肉碱的正常水平及其影响因素

Peripheral blood level of carnitine in neonates and its influencing factors

目的探讨新生儿末梢血游离肉碱的水平及其影响因素。方法 2015年1月1日至2017年12月31日,在本院分娩的新生儿中,排除原发性肉碱缺乏的患儿及母源性肉碱缺乏的小儿,共46 250例纳入研究。新生儿出生48 h后采集末梢血,采用非衍生试剂串联质谱的方法检测游离肉碱(C0)水平。根据不同性别、胎龄、出生体重、采血时日龄、是否住院治疗以及是否多胎妊娠分组,比较各组间游离肉碱水平。游离肉碱水平采用几何均数(95%CI)表示,采用Mann-Whitney U检验,Kruskal-Wallis H检验、多元线性回归进行统计学分析。结果 46 250例新生儿的游离肉碱水平为5. 21～56. 32μmol/L,几何均数为16. 05 (15. 99～16. 10)μmol/L;男性(n=24 375例)与女性(n=21 875例)分别为16. 68μmol/L与15. 38μmol/L;多胎妊娠(n=3 552例)与单胎妊娠(n=42 698例)分别为19. 22μmol/L与15. 81μmol/L;住院治疗者(n=6 409例)与非住院治疗者(n=39 841例)分别为20. 10μmol/L与15. 48μmol/L。男性、多胎、住院治疗者的血游离肉碱水平较高(Z=23. 739、30. 260、51. 336,P <0. 05)。比较8组不同胎龄、7组不同出生体重和5组不同采血时日龄的新生儿游离肉碱浓度水平,差异均有统计学意义(H=2 369. 832、3 032. 716、967. 440,P <0. 05)。经多元线性回归显示,6个因素均进入回归方程,按作用大小依次为是否住院治疗、出生体重、胎龄、是否多胎妊娠、性别、采血时日龄。结论新生儿末梢血游离肉碱水平受是否住院、出生体重、胎龄等多因素影响,因此新生儿筛查时要充分考虑上述因素对血中游离肉碱水平的影响。

Objective To determine the peripheral blood level of carnitine in neonates and to analyze its influencing factors. Methods All newborns （n = 46 250） born in Hunan provincial maternal and child healthcare hospital from 2015 to 2017 were included in this study, except for those primary earnitine deficiency and motherhood earnitine deficiency. Heel prick blood samples were collected 48 hours after birth for determination of carnitine by tandem mass spectrometry. All subjects were grouped according to gender, gestational age, birth weight, number of pregnancies, sample collecting time and whether to be hospital- ized. The level of carnitine was analyzed with Mann-Whitney U test, Kruskal-Wallis H test and mutiple linear regression. Results The free carnitine levels of 46 250 neonates were ranged from 5.21 to 56. 32 μmol/L, with a geometric mean of 16. 05 （ 15. 99 to 16. 10） μmol/L ; males （ n = 24 375 ） and females （ n = 21 875） were 16. 68 pμmol/L and 15.38 μmol/L; multiple pregnancies （n =3 552） and single pregnancies （ n = 42 698 ） were 19.22 μmol/L and 15.81 p, mol/L, respectively ; hospitalized patients （ n = 6 409 ca- ses） and non-hospitalized patients （n = 3 9841 cases） were 20. 10μmol/L and 15.48 μmol/L respectively. The levels of serum free carnitine were higher in male, multifetal and hospitalized patients （Z = 23. 739, 30. 260, 51. 336, P 〈0. 05）. Comparing the concentration of free earnitine in 8 groups with dif- ferent gestational age, 7 groups with different birth weight and 5 groups with different blood collecting age, the differences were statistically significant （H =2369. 832, 3032. 716, 967.440, P 〈0. 05）. Multivariate linear regression showed that all the six factors entered the regression equation, and the sequence was hospitalization, birth weight, gestational age, number of pregnancies, sex, blood collection age. Conclusions The peripheral blood level of carnitine in neonates is affected by many factors, such as whether to be hospitalized, birth weight, gestational age and so on.