Dynamic changes of blood free carnitine and acylcarnitine levels in premature infants receiving nutritional support / 中国新生儿科杂志

ABSTRACT

Objective To study the dynamic changes of blood carnitine and acylcarnitine levels in preterm infants during parenteral and enteral nutritional support,and the relationship between carnitine status and nutritional patterns,gestational age (GA) and weight gain.Method From January 2017 to December 2017,preterm infants admitted to the neonatal intensive care unit (NICU) within 24 hours after birth and received parenteral nutrition support were enrolled.They were assigned into 4 groups according to their GAultra-premature infants (＜ 28 weeks),very premature infants (28 ～ 31 weeks),mid premature infants (32 ～ 33 weeks) and late premature infants (34 ～ 36 weeks).They were assigned into 2 groups according to their average daily weight gain＜ 15 g/(kg · d) group and ≥15 g/(kg · d) group.Blood samples were collected and examined as dried-blood spot specimens on filter paper for four timesafter born,given total parenteral nutrition,given enteral combined parenteral nutrition,and given total parenteral nutrition.The concentrations of free carnitine and acylcarnitine were detected using liquid chromatographytandem mass spectrometry (LC-MS/MS).SPSS 21.0 statistical software was used for statistical analysis.Result A total of 124 preterm infants and 410 samples were collected.As the infants experienced gradual transition from parenteral nutrition to enteral nutrition,the free carnitine and most acylcarnitines levels were decreasing (C3,C4,C10DC,C12,C12∶1,C12DC,C14,C16,C16∶ 1,C16-OH and C18,P＜0.05).Preterm infants with small GA showed higher levels of C4-OH (P =0.001) and C5 (P =0.001).Preterm infants with lower velocity of weight gain showed lower concentration of C5-OH (P =0.006) in the early postnatal period.Conclusion Free carnitine and acylcarnitine in preterm infants during the early postnatal period are decreasing with the transition from parenteral nutrition to enteral nutrition,indicating that the exogenous nutrition is relatively insufficient.C4-OH and C5 levels are negatively correlated with GA.In addition,lower level of C5-OH may indicate slow weight gain during the early postnatal period.