Circulating monocyte chemoattractant protein-1 links to diabetic retinopathy in type 2 diabetic patients without renal dysfunction

Abstract

Monocyte chemoattractant protein-1 (MCP-1) is a cytokine thought to be an important factor in adipose tissue inflammation in obese patients, but little is known about circulating MCP-1 in type 2 diabetic patients. We studied circulating MCP-1 levels in type 2 diabetic patients and their correlation with insulin resistance and other clinical data including chronic complications. In a preliminary study of 114 non-diabetic subjects, we found a significant correlation between serum MCP-1 level and estimated glomerular filtration rate (eGFR). We thus enrolled 185 type 2 diabetic patients and 91 non-diabetic subjects with an eGFR more than 60 ml/min/1.73 m2. There was no difference in serum MCP-1 levels between diabetic patients and non-diabetic subjects. Serum MCP-1 levels had no significant correlation with high-molecular-weight adiponectin in type 2 diabetic patients. In a limited number of type 2 diabetic patients (N = 112), serum MCP-1 levels had no significant correlation with homeostasis model assessment for insulin resistance (P = 0.075). Serum MCP-1 level was higher in proliferative retinopathy patients than in non-retinopathy patients (P = 0.028). Multiple regression analysis revealed that serum MCP-1 level was correlated with diabetic retinopathy (P = 0.007). We conclude that circulating MCP-1 level has little correlation with insulin resistance but is linked with diabetic retinopathy in type 2 diabetic patients.