The correlation between insulin-like growth factor with glycemic control, glomerular filtration rate, blood pressure, hematological changes or body mass index in patients with type 2 diabetes mellitus

Insulin-like growth factor (IGF) family is made up of two polypeptides, IGF-I and IGF-II, six specific binding proteins (IGFBPs 1-6) and specific receptors. IGF-I is involved in the regulation of growth and cellular proliferation and has a similar structure to insulin. The major IGF transport function is attributed to IGFBP-3. Some studies have highlighted the association between IGF and diabetes. The aims of this study were to analyze the correlation between IGF with glycemic control, glomerular filtration rate (GFR), blood pressure, hematological changes or body mass index (BMI) in patients with type 2 diabetes mellitus (T2DM). Thirty patients with T2DM and thirty non-diabetic control patients were included in this study. Clinical, anthropometric, biochemical parameters and morphology of blood smear were recorded. Blood pressure was determined by mercury sphygmomanometer. The anthropometric measurement included BMI. The biochemical parameters included fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), GFR, serum IGF-I, IGFBP-3 levels. The IGF-I÷IGFBP-3 ratio was evaluated. The plasma glucose was determined enzymatically, HbA1c was determined by high-performance liquid chromatography (HPLC) and GFR was calculated automatically. IGF-I was measured by immunoradiometric assay (ELISA - enzyme-linked immunosorbent assay) and IGFBP-3 by sensitivity immunoassay. For the analysis of the morphology of blood smear, May-Grünwald-Giemsa (MGG) was used as staining technique. The microscopic examination was performed initially with the objectives of 10×÷20× and subsequently with an immersion objective of 100×. Image acquisition was done after the examination of the preparations obtained with a 40× objective, using Image Pro Plus 6.0 software. In the present study, we observed that T2DM leads to an increase in the IGF-I and IGFBP-3 levels. No relationship was obtain between IGF-I, IGFBP-3 levels and IGF-I÷IGFBP-3 ratio with neither parameters studied. The difference of serum IGF-I and IGFBP-3 levels between patients with T2DM and subjects without diabetes showed that IGF-I may be a useful marker for diabetes mellitus and IGFBP-3 for possible complications of this affection.