Assessment of growth factor levels in adolescents with type 1 diabetes mellitus and the beginning of diabetic microangiopathy

OBJECTIVE: The purpose of the study was the evaluation of growth hormone (GH), insulin-like growth factor (IGF-1), insulin-like growth factor binding protein (IGFBP-3) and vascular endothelial growth factor (VEGF) in adolescents with type 1 diabetes as well as the relationship between the concentration of examined proteins and the early development of diabetic microangiopathy. RESEARCH DESIGN AND METHODS: The study included 68 patients aged 15.54+/-2.9 years with type 1 diabetes. They were divided into groups: I - adolescents with the beginning of vascular complications, II - without complications. Controls consisted of healthy adolescents. GH, IGF-1, IGFBP-3 and VEGF were determined with use of ready kits. RESULTS: The increased levels of GH were found in diabetic adolescents in comparison with controls (10.11+/-16.21 vs. 2.89+/-4.03 micro IU/ml, p<0.05). The levels of IGF 1 were lower in adolescents with type 1 diabetes than in controls (283.48+/-117.36 vs. 427.95+/-177.48 ng/ml, p<0.05), as well as the levels of IGFBP-3 (5555.21+/-1158 vs. 6622.18+/-1110 pg/ml, p<0.05). Significantly higher concentration of VEGF was revealed in diabetic adolescents in comparison with controls (328.68+/-251 vs. 132.19+/-85 pg/ml, p<0.05). The highest levels of VEGF were reported in diabetic patients with retinopathy in comparison with patients without complications. CONCLUSIONS: The impaired activity of GH-IGF-1-IGFBP-3 axis may be responsible for the development of diabetic microangiopathy. The evaluation of VEGF concentration can be a sensitive early marker of microangiopathy.