Growth factors, adiponectin, leptin and body mass index in pre-pubertal children born large for gestational age

Objective: To examine whether the IGF axis in pre-pubertal children born large for gestational age (LGA) differs from that of those born appropriate for gestational age (AGA). Research design and methods: The study population consisted of 98 non-obese children aged 5.5–8 yr, of whom 37 were LGA, with birth weight (BW) >90th percentile, and 61 AGA. The LGA children were subdivided into two subgroups, with BW 90th–97th percentile (no.=24) and BW >97th percentile (no.=13), respectively. Total and free IGF-I, their binding proteins 1 and 3 (IGFBP-1 and IGFBP-3), leptin, adiponectin, fasting glucose (GF) and insulin (IF) were measured, and the homeostasis model assessment for insulin resistance (HOMA-IR index) was determined. Results: IGF-I, free IGF-I and IGFBP-1 were similar in both groups. Both LGA subgroups had lower IGFBP-3 levels than the AGA group (2.34±0.61 and 2.70±0.90, respectively, vs 3.92±1.1 μg/ml, p<0.01). Adiponectin was higher in the 90th–97th percentile LGA subgroup than the AGA group (p<0.01). GF and IF were higher in the LGA group (86.5±5.6 mg/dl, p<0.01, and 5.84±2.13 μU/ml, respectively, p<0.05) than in the AGA group (82.6±7.7 mg/dl and 4.62±1.9 μU/ml, respectively), as was the HOMA-IR index (1.27±0.60 vs 0.94±0.43, p<0.01). These three parameters were also found higher in the >97th percentile LGA subgroup. Conclusion: The IGF axis was not different in pre-pubertal children born LGA or AGA, with the exception of IGFBP-3, which was lower in the LGA children. In LGA pre-pubertal children the severity of intrauterine overgrowth was associated with the insulin resistance indices.