Study of the Correlation Between IGF-I and Glycaemic Control in Type 1 Diabetes

Diabetes is a common endocrine disease and its complications are major stimuli for the enhancment of efforts towards its control. At present, glycosylated hemoglobin (HbA1c) is used for long term control of glucose levels in diabetic patients, but due to lack of availability of a standard control method, recent findings suggest that insulin-like growth factor-I (IGF-I) may be used as a biomarker for glycaemic control. The aim of this study was to examine the correlation between IGF-I and glycaemic control measured as fasting plasma glucose (FPG) and HbA1c in Type 1 diabetes. We designed a crosssectional case-control study with systematic random sampling. The study included 26 newly diagnosed patients with Type 1 diabetes (15 male and 11 female; mean age 23.7±9.1 years) and 26 healthy controls (9 male and 17 female; mean age 24.1±4.4 years). The concentrations of FPG, IGF-I, HbA1c and IGF-binding protein-3 (IGFBP-3) were measured in both groups. FPG was measured by the enzymatic glucose oxidase method and the colorimetric method was used tomeasure HbA1c. Determination of serum IGF-I and IGFBP-3 total levels was carried out using immunoassay. P<0.05 was considered as statistically significant. The mean value of IGF-I concentration in Type 1 diabetics was significantly lower than in controls (p<0.05). No correlation was found between IGF-I and HbA1c in the patients. Our data shows that total IGF-I levels are low in patients with Type 1 diabetes. No relationship was found between IGF-I and glycaemic control. However, more detailed intensive studies to further investigate this relationship are recommended.