The effects of maternal diet during late pregnancy and body shape at birth on postnatal plasma concentrations of insulin like growth factor 1 (IGF1) and leptin
JC Litten, KS Perkins, AM Corson, IJ Lean & L Clarke
This study examined the effects of maternal diet during late pregnancy and body shape at birth, on postnatal plasma concentrations of IGF1 and leptin.
From day 85 of gestation pregnant sows were offered the standard diet (S: n=4) or the S diet plus 30% extra energy derived from either carbohydrate (C: n=5) or palm oil (PO: n=5). Piglets were selected from the normal distribution curve of Ponderal Index (PI: kg/m3), long and thin (Thin<10 th), normal (N: 10th-90th) and short-for-weight (Fat >90th). Blood samples were taken on day 3 and again on day 150±4 of life (S n=52: C, n=44: P, n=43). Differences between groups were assessed using General Linear Model, ANOVA, with body weight as a covariate.
Supplementation during pregnancy enhanced neonatal leptin (S, 1.6±1.3: C, 3.0±1.2: PO, 4.6±1.9 ng/ml: mean±SEM: P<0.05) and IGF1 (S, 35±6: C, 50±6: PO, 47±7 micrograms/ml: P<0.01) concentrations on day 3 but there were no differences between the PI groups. Thin pigs born to S sows had higher plasma leptin and IGF1 by 150±4 days of age, whereas these hormones were reduced in the PO group (Leptin S, 8.6±2.3: PO, 2.8±1.8 ng/ml Human Equivalent (HE): IGF1 S, 211±36: PO, 55±35 micrograms/ml: P<0.05). Interestingly, the situation was reversed in Fat pigs (Leptin S, 3.1±2.1: PO, 9.1±2.2 ng/ml HE: IGF-1 S, 75±35: PO, 137±30 μg/ml: P<0.05).
In conclusion, thin pigs at birth have elevated concentrations of IGF1 and leptin in later life, which may in part be due catch up growth and enhanced promotion of fat deposition, similar to that seen in human babies that are long and thin at birth. In contrast, a high lipid diet in pregnancy appears to offer some protection against obesity in thin offspring.
This work was funded by DEFRA.