Protective effect and mechanism of C peptide on type 2 diabetic nephropathy

Objective To study the protective effect of C - peptide on diabetic nephropathy and its mechanism.Methods Sixty - six cases of type 2 diabetes were divided into two groups( insulin therapy group and insulin secretagogue therapy group).Age,sex,BMI,course of disease were recorded and fasting blood glucose,plasma C -peptide levels and glycated hemoglobin were detected. Erythrocyte membrane ATPase activity and the level of plasma nitric oxide were detected by enzyme colorimetrie method.The relationships between C - peptide levels and the stages of diabetic nephropathy in type 2 diabetes were analyzed.Results ①Erythrocyte membrane ATPase activity and plasma nitric oxide levels were lower in insulin therapy group than those in insulin secretagogue therapy group (P ＜ 0.05 ).②In type 2 diabetes,erythrocyte membrane ATPase activity was positively correlated with plasma C -peptide and insulin levels,while erythrocyte membrane ATPase activity was negatively correlated with course of disease and age.③The phases of diabetic nephropathy gradually increased accompany with the decrease of plasma C - peptide level.Conclusions C - peptide could reduce kidney damage in type 2 diabetic nephropathy by elevating erythrocyte membrane ATPase activity. Key words: C - peptide; Insulin; Type 2 diabetes; Diabetic nephropathy