INTRODUCTION. The aim of the study was evaluation of the somatic development and sexual maturation of children and adolescents with type 1 diabetes mellitus and estimation of their IGF-IGFBP system at the on-set of diabetes as well as during the progress of the disease. It was also analysed how the methods of insulinotherapy influence estimated growth factors and auxology parameters.
MATERIAL AND METHODS. 148 diabetic patients without other diseases treated with conventional and intensive insulinotherapy with diabetes duration 0-21 years and 54 age-matched healthy children and adolescents 2–22 years old were included into the study. Their somatic and pubertal development were estimated by experienced physician and anthropologist. Blood samples were taken at 7.30–8.30 a.m., after 8h fasting. The serum concentrations of IGF-I were measured by RIA; IGFBP-1 and IGFBP-3 concentrations by IRMA and HbA_1c by HPLC method. The data were analysed using test t-Student, ANOVA, linear and multiple regression analyses.
RESULTS. The diabetic patients’ height did not differ from the height of healthy children and adolescents. At the onset of diabetes patients were not significantly taller than their healthy contemporaries but with the disease duration progress their growth slowly decreased and finally they reached lower level of height than in the control group (the difference didn’t reach statistical significance). Sexual maturation of diabetic patients did not differ from age related healthy polish population independently of diabetes duration. All diabetic and healthy children’s z score of height were higher than z score of mid-parental height. IGF-I concentrations were lower and IGFBP-3 concentrations were higher in diabetic patients than in the control group. IGFBP-1 levels did not differ in both groups. Before the onset of puberty patients’ height correlated with IGF-I, IGFBP-1, and IGFBP-3. In all diabetic patients height correlated with insulin requirement. IGF-1 concentrations correlated also with insulin requirement and HbA1c. Diabetic patients treated with intensive insulinotherapy were slightly taller and had higher IGF-1 and lower IGFBP-1 concentrations than patients treated with other methods of insulinotherapy.
CONCLUSIONS. Somatic development of diabetic children depends not only on genetic influence, but also on adequate insulin substitution which could be achieved by intensive insulinotherapy. Despite decreased IGF-I levels, height within normal ranges was attained, probably because of adequate insulin compensation leading to normal IGFBP-1 levels, thus adequate IGF-I bioavailability.