Preterm birth and the endocrine regulation of growth in childhood and adolescence

Objective Poor growth during childhood is a common problem associated with preterm birth, but few studies have examined the associations between linear growth, weight and body composition with the postnatal hormonal milieu in preterm children. We aimed to define the IGF-IGFBP axis in preterm children and its association with growth. Design and patients A cohort of healthy 2- to 20-year-old subjects who were born prematurely (<37 weeks gestation) and experienced normal neurological development were recruited. In total, 54 premature and 82 control subjects were included in this study. Results Preterm subjects were relatively shorter (P < 0.001) and leaner (P < 0.05) than their parents in contrast to the term cohort. Preterm children also appeared to fail to reach their genetic height potential (prepuberty: P < 0.01; puberty: P < 0.05). Only IGFBP-2 differed between preterm and term cohorts, with higher levels observed in prepubertal preterm subjects (P < 0.01). In the term group, height SDS was positively associated with IGF-I (P < 0.01) and IGFBP-3 (P < 0.001) concentrations, but no such associations were observed for preterm subjects. Conclusion Preterm children are shorter and lighter than controls throughout childhood, remaining below their genetic height potential. Preterm birth appears to alter the endocrine regulation of postnatal growth in childhood and adolescence, so growth is no longer associated with its normal endocrine regulators.