Effects of postnatal age and diet on the fatty acid composition of plasma lipid fractions in preterm infants.
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.
Pita
M L
ML
Department of Biochemistry, University of Granada, Spain.
Girón
M D
MD
Pérez-Ayala
M
M
DeLucchi
C
C
Martínez Valverde
A
A
Gil
A
A
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
D002788:Cholesterol Esters; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D008055:Lipids; D010743:Phospholipids; D014280:Triglycerides