Increased IGFBP-1 Levels Relating to Low IGF-I in Diabetic Children

Abstract

It is known that retarded growth is caused by low IGF-I due to poor metabolic control in children with insulin-dependent diabetes mellitus (IDDM). Our study aims to clarify whether increased levels of insulin-like growth factor binding protein-I (IGFBP-1) reflect low IGF-I production. Nine prepubertal and 25 adolescent IDDM patients were studied in a fasting condition, early on the same morning. IGF-I, IGFBP-1, IGFBP-3, free insulin (IRI), blood glucose and other metabolic parameters were assayed. IGF-I levels were low, with high IGFBP-1 and low IGFBP-3, in IDDM according to pubertal stages. IGFBP-1 showed inverse correlation with IGF-I in adolescent IDDM. Since both IGFBP-1 and IGF-I showed closer correlation with fasting blood glucose than hemoglobin (Hb) Alc levels, the co-factors may be involved in fasting metabolic disturbance rather than overall hyperglycemia. IGFBP-1 showed inverse correlation with fasting free IRI whose levels themselves were not so low, while free fatty acids were not so high and correlated positively with IGFBP-1. These findings indicate that attention should be paid to hepatic insulin deficiency and overnight hypoglycemia in the treatment of IDDM.