Analysis of amino acid and acylcarnitine profile in full-term newborns small for gestational age / 中华实用儿科临床杂志

ABSTRACT

Objective:To compare the difference of blood amino acids and acylcarnitine levels between small-for-gestational-age (SGA) and appropriate-for-gestational age (AGA) full-term newborns, and to explore the changes of the blood metabolism spectrum of full-term SGA, so as to provide evidence for clinical intervention.Methods:Seventy-nine full-term SGA newborns born in the Sixth Affiliated Hospital of Sun Yat-Sen University from January to December 2018 were selected as the study objects.Seventy-nine gestational age-and gender-matched healthy full-term AGA newborns born in the same hospital at the same time were selected as the control group.The dry blood spot samples were collected and detected by tandem mass spectrometry on the third day after birth.The differences between two groups and considerable biomarkers were explored by the orthogonal partial least squares discriminant analysis (OPLS-DA).Results:The birth weight of SGA newborns was (2.5±0.2) kg, and that of AGA newborns was (3.2±0.3) kg.OPLS-DA model analysis showed that 12 kinds of blood metabolites were identified which possessed the biggest weight discriminating the full-term SGA group from the AGA group, and the ratios of these blood metabolites of two groups were compared as follows propionylcarnitine (0.34±0.13 vs. 0.42±0.15), tyrosine [0.24(0.18, 0.27) vs.0.28(0.22, 0.37)], free carnitine (0.43±0.14 vs. 0.37±0.12), valine [0.39(0.35, 0.45) vs.0.44(0.36, 0.53)], octanoylcarnitine (0.33±0.13 vs. 0.29±0.09), myristoylcarnitine (0.35±0.12 vs. 0.31±0.10), butylcartine (0.37±0.13 vs. 0.41±0.14), 3-hydroxyisovlerylcartine[0.35(0.25, 0.43) vs.0.35(0.26, 0.45)], decenoylcarnitine (0.26±0.13 vs. 0.23±0.08), isovalerylcarnitine[0.33(0.26, 0.34) vs.0.33(0.30, 0.35)], leucine [0.38(0.30, 0.47) vs.0.40(0.33, 0.48)]and methionine (0.42±0.14 vs. 0.46±0.15). The level of propionylcarnitine ( t=3.920), tyrosine ( Z=3.536) and valine ( Z=2.838) in the full-term SGA group were significantly lower than those in the AGA group, while the levels of free carnitine ( t=-2.863), octanoylcarnitine ( t=-2.266) and myristoylcarnitine ( t=-2.194) in the full-term SGA group were significantly higher than those in the AGA group (all P<0.05). Conclusions:The concentration of amino acids and acylcarnitine in the blood of SGA newborns is different from that in AGA newborns.Aromatic amino acids and branched chain amino acids should be added in full-term SGA nutrition support as they can meet the energy metabolism by mobilizing medium and long chain fatty acids in the early stage.