NONINVASIVE CHARACTERIZATION OF NEONATAL ADIPOSE-TISSUE BY C-13 MAGNETIC-RESONANCE SPECTROSCOPY

In vivo C-13 magnetic resonance spectroscopy (MRS) was applied noninva sively to analyze the fatty acid composition of adipose tissue in 21 f ull-term newborn infants and 6 mothers, In order to assess the effects of gestational and postnatal age on adipose tissue composition, we st udied preterm infants at birth, term infants at the ages of 6 wk and a t 6 mon. We also investigated the influence of maternal diet on infant adipose tissue composition by studying the breast-fed infants of wome n who maintained either an omnivore or a vegan diet. Significant diffe rences were observed in adipose tissue composition of neonates compare d with their mothers. Neonates had more saturated and less unsaturated fatty acids than their mothers(Pi 0.01). We also observed changes in adipose tissue composition with maturity. From birth to 6 wk of age C- 13 MR spectra showed a significant increase in the amount of unsaturat ed fatty acids, particularly polyunsaturated fatty acids(P < 0.01). Si milarly, differences were seen as a result of gestational age. Preterm infants had relatively fewer unsaturated fatty acids than full-term i nfants. A greater proportion of these unsaturated fatty acids were pol yunsaturated. Our results demonstrate that C-13 MRS can be utilized to assess noninvasively neonatal adipose tissue lipid composition and to monitor the effects of developmental changes due to gestational age a nd oral feeding.