Background : The IGF system is involved in the development of metabolic and cardiovascular disease. This study aimed to investigate the association of insulin-like growth factor-1 (IGF-1), IGF-binding protein-1 (IGFBP-1) and IGFBP-3 with insulin resistance and type 2 diabetes in children.
Methods : We included 36 children aged 10 to 16 years without known diabetes, medication, chronic disease. They were classified into 3 groups according to the results of oral glucose tolerance test and other clinical/laboratory findings. We performed anthropometric measurement and laboratory tests. The fasting levels of serum IGF-1, IGFBP-1 and IGFBP-3 were measured.
Results : 1) Serum IGF-1, IGFBP-3 and IGF-1/IGFBP-1 molar ratio levels were significantly higher in glucose intolerance group. Serum IGF-1(r=-0.396, P=0.023) and IGFBP-3(r=-0.628, P<0.001) had negative correlation with IGFBP-1. 2) Serum IGFBP-1 was negatively correlated with age, body mass index (BMI), systolic blood pressure, serum c-peptide, insulin, and HOMA-IR. And serum IGF-1/IGFBP-1 was significantly related with serum c-peptide, insulin and HOMA-IR. 3) Serum IGFBP-1 had no correlation with fasting plasma glucose level, lipid profile, apoprotein A/B and HbA1c. It was not different between normal glucose tolerance group and glucose intolerance group. 4) In normal glucose tolerance group, serum IGFBP-1 and IGF-1/IGFBP-3 was no significantly different between obese and non-obese groups. But IGFBP-1 had negatively associated with age, BMI, systolic blood pressure, serum c-peptide, IGFBP-3 and HOMA-IR.
CONCLUSION: Serum IGF-1/IGFBP-1 molar ratio was significantly elevated in Korean children with glucose intolerance sate and especially, serum IGFBP-1 correlated with serum c-peptide. These findings suggest that IGFBP-1 may related glycemic control and insulin secretion in children.