Insulin-like growth factor-1 and its binding proteins, IGFBP-1 and IGFBP-3, in adolescents with type-1 diabetes mellitus and microalbuminuria.
OBJECTIVE
Numerous clinical and experimental studies suggest that growth factors may contribute to the development of diabetic microvascular complications. The aim of the study was to test the hypothesis that in adolescents with type-1 diabetes mellitus and microalbuminuria (MA) there are specific disorders of serum insulin-like growth factor-1 (IGF-1) and concentrations of its binding proteins, IGFBP-1 and IGFBP-3, that could be of importance in the pathogenesis of microvascular diabetic complications.


METHODS
25 adolescents with MA, 24 adolescents with diabetes without complications, and 17 controls were examined. There were no differences with regard to age, puberty stage, HbA1c and body mass index between the groups examined. Two of the patients in the first group also had diabetic retinopathy. Serum fasting concentrations of IGF-1 and overnight urine albumin concentrations were measured by radioimmunoassay, IGFBP-1 and IGFBP-3 concentrations by immunoradiometric assay and HbA1c by high-performance liquid chromatography methods. Diabetic patients were examined by an experienced ophthalmologist and neurologist. The data were analyzed using Kruskal-Wallis ANOVA and multiple regression analysis.


RESULTS
Significantly lower IGF-1 concentrations were found in adolescents with diabetes and MA compared to diabetic patients without complications and healthy contemporaries. IGFBP-1 concentrations were significantly higher and IGFBP-3 concentrations were statistically lower in diabetic patients with MA than in patients without complications.


CONCLUSIONS
The IGF-IGFBP system is deranged in adolescents with type-1 diabetes mellitus and MA. Our results suggest the participation of circulating IGFBP-1 in the origin of diabetic complications. It could be also possible that IGFBP-3 takes part in the protection from them.
Wedrychowicz
Anna
A
Department of Pediatric Endocrinology, Polish-American Children's Hospital, Jagiellonian University, Kraków, Poland. miniedzw@cyf-kr.edu.pl
Dziatkowiak
Hanna
H
Nazim
Joanna
J
Sztefko
Krystyna
K
D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000097:blood* / Q000150:complications; D001794:Blood Pressure; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000150:complications; D003925:Diabetic Angiopathies / Q000097:blood; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D012044:Regression Analysis
D006442:Glycated Hemoglobin; D018970:Insulin-Like Growth Factor Binding Protein 1; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I