Correlation of retinopathy with serum levels of growth hormones and insulin-like growth factor-1 in patients with diabetic retinopathy

Objective: This study aims to retrospectively analyze the correlation between levels of serum growth hormones and insulin-like growth factor-1 (IGF-1) and severity of retinopathy in type 2 diabetes patients reaching the goal of blood glucose control. Method: A retrospective analysis was adopted for 112 type 2 diabetes patients reaching the goal of blood glucose control in the past 3 years. All patients received fundus fluorescein angiography, based on which the patients were divided into normal fundus group, non-proliferative diabetic retinopathy (DR) group and proliferative DR group. The three groups were compared with regard to the levels of serum growth hormones and IGF-1. Their correlation with severity of DR was assessed using multivariate unconditional logistic regression. Result: In the proliferative DR group, the levels of low density lipoprotein cholesterol (LDL-C), urine micro albumin (UmALB), serum growth hormones and IGF-1 were all significantly higher than those of the normal group and the non-proliferative DR group (P<0.05); however, no significant difference was found between the non-proliferative DR group and the normal group (P>0.05). The C-peptide (C-P) level in the proliferative DR group was markedly lower than that of the other two groups (P<0.05); but no significant difference was found between the non-proliferative DR group and the normal group (P>0.05). As indicated by correlation analysis, course of disease, UmALB, IGF-1 and fasting C-P levels were correlated to the severity of DR. Conclusion: The common factors of DR are course of diabetes, systolic pressure, LDL-C, fasting C-R risk and UmALB. In addition to these, higher levels of serum growth hormones and IGF-1 may also contribute to DR, which is speculated to be one mechanism for the progression of DR in type 2 diabetes.