Insulin-like growth factor [IGF] -1, IGF-II, IGF-binding protein -1 [IGFBP-1] and IGFBP-3 in children with insulin dependent diabetes mellitus

ABSTRACT

The existing literature on serum insulin like growth factors [IGFs] and their binding proteins [IGFBPs] levels in insulin dependent diabetes mellitus [IDDM] is conflicting. In the present study, 44 children and adolescents with IDDM [22 newly diagnosed and 22 old known cases] aged from 5 to 14 years, 18 girls and 26 boys, together with 18 apparently healthy control children of matchable age and sex were subjected to estimation of serum levels of IGF-I, IGF II, IGFBP-1, IGFBP-3 and fasting serum glucose. Glycemic control was assessed by glycosylated hemoglobin [HbA[1C]]. Diabetic children showed significantly lower serum levels of IGF-I, IGF-II and IGFBP-3 [p<0.01, p<0.01 and p<0.001 respectively] and significantly higher levels of IGFBP-1 [p<0.05] than controls. This was true for the diabetic cases in general, for newly diagnosed cases and for those with poor metabolic control. Old diabetic cases and patients with average glycemic control differed from the control children only regarding IGF-II [p<0.001 for both] and regarding IGFBP-3 [p<0.001] and p<0.05 respectively]. While prepubertal cases showed significantly lower IGF-I than controls [p<0.05], pubertal cases lacked this difference. IGF-I levels were negatively correlated with each of HbA[1C] [r=-0.52, p<0.001] and IGFBP-1 [r=-0.45, p<0.002], and were positively correlated with each of IGFBP 3 [r=0.31, p<0.05] and body mass index [BMI] [r=0.43, p<0.004]. IGFBP-1 levels were positively correlated with fasting serum glucose [r=0.46, p<0.002]. In conclusion, alterations in the IGF/IGFBP system are observed in children with IDDM in the present study. Improvement of glycemic control may help to decrease this alteration. The impact of these alterations on the health of diabetic children is still unsettled