BACKGROUND: Early postnatal growth retardation with subsequent catch-up growth is common in preterm infants. We describe a model of ex utero (postnatal) growth retardation followed by varying degrees of catch-up growth in the neonatal rat. METHODS: Newborn CD rat pups were randomized to litters of 10 (NN, normal then normal intake) or 16 (R, restricted intake). On day 10, R pups were further randomized to litters of 6 (RC, restricted then catch-up intake), 10 (RN, restricted then normal intake), or 16 (RR, restricted then restricted intake). Body weight, body composition, insulin sensitivity, biochemistry, and learning (passive avoidance test) were assessed. RESULTS: Growth was significantly lower in the R than the NN group. Subsequently, the RC group caught up with the NN group but had higher fat mass; the RN group showed partial catch-up but body composition similar to that of the NN group. Insulin sensitivity did not differ between groups. Learning behavior was significantly better in the NN than the three R groups, and in the RC group than the RR or RN groups. CONCLUSION: Early postnatal growth retardation is associated with poorer medium-term growth and poorer developmental outcome. Increased catch-up growth is associated with improved developmental outcome but with increased body adiposity, without any significant effect on glucose homeostasis.
BACKGROUND: Early postnatal growth retardation with subsequent catch-up growth is common in preterm infants. We describe a model of ex utero (postnatal) growth retardation followed by varying degrees of catch-up growth in the neonatal rat. METHODS: Newborn CD rat pups were randomized to litters of 10 (NN, normal then normal intake) or 16 (R, restricted intake). On day 10, R pups were further randomized to litters of 6 (RC, restricted then catch-up intake), 10 (RN, restricted then normal intake), or 16 (RR, restricted then restricted intake). Body weight, body composition, insulin sensitivity, biochemistry, and learning (passive avoidance test) were assessed. RESULTS: Growth was significantly lower in the R than the NN group. Subsequently, the RC group caught up with the NN group but had higher fat mass; the RN group showed partial catch-up but body composition similar to that of the NN group. Insulin sensitivity did not differ between groups. Learning behavior was significantly better in the NN than the three R groups, and in the RC group than the RR or RN groups. CONCLUSION: Early postnatal growth retardation is associated with poorer medium-term growth and poorer developmental outcome. Increased catch-up growth is associated with improved developmental outcome but with increased body adiposity, without any significant effect on glucose homeostasis.
Authors: Marta L Fiorotto; Teresa A Davis; Horacio A Sosa; Carolina Villegas-Montoya; Irma Estrada; Ryan Fleischmann Journal: J Physiol Date: 2014-09-19 Impact factor: 5.182
Authors: Stephen Wedgwood; Cris Warford; Sharleen C Agvateesiri; Phung Thai; Sara K Berkelhamer; Marta Perez; Mark A Underwood; Robin H Steinhorn Journal: Pediatr Res Date: 2016-08-10 Impact factor: 3.756
Authors: Stephen Wedgwood; Cris Warford; Sharleen R Agvatisiri; Phung N Thai; Nipavan Chiamvimonvat; Karen M Kalanetra; Satyan Lakshminrusimha; Robin H Steinhorn; David A Mills; Mark A Underwood Journal: Pediatr Res Date: 2019-09-19 Impact factor: 3.756