ESPE Abstracts

Background: IGF1 is important for fetal and infant growth and is influenced by nutrition. In young pigs, docosahexaenoic acid (DHA)-enriched food is associated with higher IGF1 levels but studies in human infants are lacking.

Aims and objectives: To assess levels of polyunsaturated fatty acids (PUFA) relate to IGF1, birth size and growth during infancy.

Methods: The setting was a population-based longitudinal cohort comprising 126 full-term, normal size infants (50% females) followed prospectively with anthropometric measurements as well as blood sampling from cord blood, serum at 2 days of age and at four and 12 months. Only those which had complete series of PUFA analyses were included. Parents completed food questionnaires on each occasion. At 1 month of age, 95% were given some breastfeeding and at four months 64% were exclusively breastfed. IGF1 were assessed using the IDS-iSYS-technique and leptin using RIA (Linco Research). Essential fatty acids were analysed with masspectrometry technique.

Results: Cord IGF1 correlated negatively to cord omega n6/n3 (r=−0.25, P<0.01) and cord arachidonic acid (AA) (r=−0.34, P<0.001). At birth, AA had a negative correlation to birth length (BL) (r=−0.29, P=0.001) and weight (BW) (r=−0.25, P<0.01). The unsaturated PUFA mead acid from cord blood and at two days of age correlate closely to BW (r=0.45, P<0.001), BL (r=0.34, P<0.001) and head circumference (r=0.35, P<0.001). At 2 days of age, there was a negative correlation between IGF1 and AA (r=−0.52, P<0.001) and a positive correlation to linoleic acid (LA) (r=0.46, P<0.001) respectively. At 4 months of age IGF1 still correlated positively to LA (r=0.39, P>0.001) but negatively to omega n3/n6 ratio (r=−0.40, P<0.001) and to AA (r=−0.36, P<0.001).

Conclusions: During infancy, essential fatty acids correlate to IGF1 and to birth size. Whether this is through GH level or nutrition per se remains to be elucidated.