title: Synthesis of long-chain polyunsaturated fatty acids in preterm newborns fed formula with long-chain polyunsaturated fatty acids.
abstract: BACKGROUND
  Docosahexaenoic acid (DHA) and arachidonic acid (AA) are long-chain polyunsaturated fatty acids (LCPs) that play pivotal roles in growth and neurodevelopment.
  
  
  OBJECTIVE
  We aimed to quantify the synthesis of LCPs in preterm infants fed infant formula containing LCPs.
  
  
  METHODS
  Twenty-two preterm infants were randomly assigned to either the no-LCP group (fed formula without LCPs; n = 11) or the LCP group (fed formula with LCPs; n = 11). Dietary LCPs had higher (13)C content than did the endogenously synthesized LCPs, which were derived from linoleic and alpha-linolenic acids. The (13)C content of major selected plasma fatty acids was measured by using gas chromatography-isotope ratio mass spectrometry at birth and at age 1, 3, and 7 mo. Absolute LCP synthesis and the percentage of LCP synthesis relative to dietary intake were calculated.
  
  
  RESULTS
  Percentage AA synthesis was 67.2 +/- 7.8%, 35.9 +/- 9.8%, and 29.0 +/- 10.3%, and that of DHA was 41.7 +/- 14.9%, 10.5 +/- 8.1%, and 7.4 +/- 6.2% at 1, 3, and 7 mo old, respectively. Absolute AA synthesis was 26.7 +/- 4.2, 14.4 +/- 3.9, and 11.6 +/- 4.1 mg x kg(-1) x d(-1) and that of DHA was 12.6 +/- 4.5, 3.2 +/- 2.5, and 2.3 +/- 1.9 mg x kg(-1) . d(-1) at 1, 3, and 7 mo old, respectively. AA and DHA synthesis decreased significantly (P < 0.01) with time, and AA synthesis was significantly (P < 0.01) greater than DHA synthesis.
  
  
  CONCLUSIONS
  By this novel approach, we measured endogenous LCP synthesis in infants receiving dietary LCPs over long periods. By age 7 mo, LCP synthesis was dramatically lower in preterm infants fed LCPs.
authors.affiliation: Division of Neonatology, Institute of Maternal-Infantile Sciences, Polytechnic University of Marche, Ancona, Italy. lab2@pediatria.unipd.it
authors.forename: Virgilio P
authors.initials: VP
authors.lastname: Carnielli
authors.forename: Manuela
authors.initials: M
authors.lastname: Simonato
authors.forename: Giovanna
authors.initials: G
authors.lastname: Verlato
authors.forename: Ingrid
authors.initials: I
authors.lastname: Luijendijk
authors.forename: Mario
authors.initials: M
authors.lastname: De Curtis
authors.forename: Pieter Jj
authors.initials: PJ
authors.lastname: Sauer
authors.forename: Paola E
authors.initials: PE
authors.lastname: Cogo
mesh_terms: D016718:Arachidonic Acid / Q000096:biosynthesis; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D004281:Docosahexaenoic Acids / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D041943:Infant Formula; D007231:Infant, Newborn; D007234:Infant, Premature; D010743:Phospholipids / Q000097:blood
chemical_list: D004042:Dietary Fats, Unsaturated; D005231:Fatty Acids, Unsaturated; D010743:Phospholipids; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid