title: Effects of postnatal age and diet on the fatty acid composition of plasma lipid fractions in preterm infants.
abstract: Diet and postnatal age effect the fatty acid composition of plasma and tissue lipids. This work was designed as a transversal study to evaluate the changes in the fatty acid composition of plasma phospholipids, cholesteryl esters, triglycerides and free fatty acids in preterm infants (28-35 weeks gestational age), fed human milk (HM) and milk formula (MF) from birth to 1 month of life. Sixteen blood samples were obtained from cord, and 19 at 6-8 h after birth, 14 at 1 week and 9 at 4 weeks from HM-fed infants and 18 at 1 week and 14 at 4 weeks from MF-fed ones. Groups had similar mean birth weight, gestational age and sex ratio. The MF provided 69 kcal/dl and contained 16% of linoleic acid and 1.3% of alpha-linolenic acid on the total fat. Plasma lipid fractions were extracted and separated by thin-layer chromatography and fatty acid methyl esters were quantitated by gas liquid chromatography. In plasma phospholipids, linoleic acid (18:2 omega 6) continuously increased from birth to 1 month of age, but no changes were seen as related to type of diet; polyunsaturated fatty acids greater than 18 carbon atoms of both the omega 6 and omega 3 series (PUFA omega 6 greater than 18 C and omega 3 greater than 18 C) dropped from birth to 1 week and continued to decrease in MF-fed infants until 1 month; eicosatrienoic (20:3 omega 6), arachidonic (20:4 omega 6) and docosahexaenoic (22:6 omega 3) were the fatty acids implicated. In cholesteryl esters palmitoleic (16:1 omega 7) and oleic (18:1 omega 9) acids decreased from birth to 1 month and linoleic acid increased and arachidonic acid dropped, especially in MF fed infants. In triglycerides, palmitic, palmitoleic and stearic acid (18:0) decreased during the first month of life; oleic acid remained constant and linoleic acid increased in all infants, but arachidonic acid decreased only in those fed formula. Free fatty acids showed a similar behavior in fatty acids and in plasma triglycerides. Preterm neonates seem to have special requirements of long-chain PUFA and adapted MF should contain these fatty acids in similar amounts to those of HM to allow the maintenance of an adequate tissue structure and physiology.
authors: Department of Biochemistry, University of Granada, Spain.
authors: M L
authors: ML
authors: Pita
authors: M D
authors: MD
authors: Girón
authors: M
authors: M
authors: Pérez-Ayala
authors: C
authors: C
authors: DeLucchi
authors: A
authors: A
authors: Martínez Valverde
authors: A
authors: A
authors: Gil
mesh_terms: D000375:Aging / Q000097:blood*; D002788:Cholesterol Esters / Q000097:blood; D005227:Fatty Acids / Q000097:blood*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006801:Humans; D007225:Infant Food; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood* / Q000254:growth & development; D008055:Lipids / Q000097:blood*; D008895:Milk, Human; D010743:Phospholipids / Q000097:blood; D014280:Triglycerides / Q000097:blood
chemical_list: D002788:Cholesterol Esters; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D008055:Lipids; D010743:Phospholipids; D014280:Triglycerides