با رتينوپاتي ديابتي IGFBP-3 و IGF-1 مطالعه ارتباط بين ميزان سطوح سرمي

Study of correlation between serum total IGF-1 and IGFBP-3 levels and diabetic retinopathy

Introduction: Diabetes mellitus is the most common endocrine disease and diabetic retinopathy (DR) is one of its most important ophthalmic complications. It is supposed that insulin-like growth factor-1 (IGF-1) is one of the probable causative factors on formation and promotion of retinopathy. The aim of this study is to evaluate the correlation between serum total IGF-1 and IGF-binding protein-3 (IGFBP-3) levels and DR. Materials and Methods: We designed a case-control study with systematic random sampling. Sixty-three diabetic patients with no history of hypertension were examined by retinal fundoscopy, and divided into two groups (control group without retinopathy and case group with retinopathy). The serum level of fasting blood sugar (FBS) was measured by enzymatic glucose oxidase and glycosylated hemoglobin (HbA1c) by colorimetric method. Total IGF-1 and IGFBP-3 levels were measured by immunoassay. Results: The incidence and severity of retinopathy, increased significantly with increasing age and duration of diabetes (p<0.05), but there was no correlation between retinopathy and serum levels of FBS, HbA1c, IGF-1 and IGFBP-3. There was a significant inverse correlation between age and IGF-1 in both control and case groups (p<0.05). There was a significant direct correlation between total levels of IGF-1 and IGFBP-3 in the case group (p<0.02). Conclusion: Our data showed that serum levels of total IGF-1 and IGFBP-3 were not correlated significantly with incidence and severity of retinopathy. However, it is postulated that with increasing sample size, the role of IGF-1 and its binding proteins as causative factors will be clear.