title: Metabolic products in urine of preterm infants characterized via gas chromatography-mass spectrometry.
abstract: OBJECTIVE
  To characterize the metabolic products of urine associated with preterm birth, thus providing clinical guidelines for intestinal and parenteral nutrition in preterm infants.
  
  
  METHODS
  Urine samples of 47 preterm infants and 45 full-term infants were collected and prepared for trimethylsilylation by treatment with urease. The levels of lysine, phenylalanine, histidine, ornithine, fumaric acid, malic acid, succinic acid, lactose, stearic acid, and 4-hydroxyphenylacetic acid were detected by gas chromatography-mass spectrometry (GC/MS), and statistically analyzed.
  
  
  RESULTS
  The normalized concentrations of the following metabolites in preterm infant urine samples were significantly lower than that of full-term infant urine samples: lysine (P = 0.003), phenylalanine (P = 0.001), histidine (P = 0.006), ornithine (P = 0.000), fumaric acid (P = 0.002), malic acid (P = 0.006), succinic acid (P = 0.000), lactose (P = 0.000), stearic acid (P = 0.000) and 4-hydroxyphenylacetic acid (P = 0.000).
  
  
  CONCLUSIONS
  The results of the GC/MS analysis indicated that amino acid, carbohydrate, and fatty acid metabolism defects exist in preterm infants. The use of GC/MS to determine metabolic products in urine samples could be helpful for prospectively evaluating the nutritional status of preterm infants, and therefore providing clinical guidelines on reasonable nutritional support.
authors.affiliation: Department of Neonatology, Sixth Affiliated Hospital of Sun Yat-Sen University Guangzhou 510655, China ; Laboratory of Inborn Errors of Metabolism, Sixth Affiliated Hospital of Sun Yat-Sen University Guangzhou 510655, China.
authors.forename: Hu
authors.initials: H
authors.lastname: Hao
authors.affiliation: Department of Neonatology, Sixth Affiliated Hospital of Sun Yat-Sen University Guangzhou 510655, China.
authors.forename: Sitao
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Neonatology, Guangzhou Women and Children Medical Center Guangzhou 510623, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Neonatology, Tianhe Women and Children Hospital Guangzhou 510620, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Neonatology, Sixth Affiliated Hospital of Sun Yat-Sen University Guangzhou 510655, China.
authors.forename: Mengxian
authors.initials: M
authors.lastname: Liu
authors.affiliation: Laboratory of Inborn Errors of Metabolism, Sixth Affiliated Hospital of Sun Yat-Sen University Guangzhou 510655, China.
authors.forename: Congcong
authors.initials: C
authors.lastname: Shi
authors.affiliation: Laboratory of Inborn Errors of Metabolism, Sixth Affiliated Hospital of Sun Yat-Sen University Guangzhou 510655, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Neonatology, Sixth Affiliated Hospital of Sun Yat-Sen University Guangzhou 510655, China ; Laboratory of Inborn Errors of Metabolism, Sixth Affiliated Hospital of Sun Yat-Sen University Guangzhou 510655, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Xiao
keywords: Preterm infant; full-term infant; gas chromatography-mass spectrometry; metabolic product; urease treatment