Introduction. Copeptin is the carboxy-terminal fragment of the vasopressin precursor (pre-pro-vasopressin); it is a surrogate marker of plasma levels of vasopressin and a prognostic marker of mortality in chronic heart failure. Recently, plasma levels Copeptin were associated with microalbuminuria concentration.

Objective: To determine if plasma levels of Copeptin are associated with declination of renal function in patients with type 2 diabetes.

Methods. In a cross-sectional study, 656 patients with type 2 diabetes were analyzed. Declination of renal function was classified according the K-DOQI guidelines. Cockroft-Gault equation was adjusted by body weight; plasma Cystatin C was utilized to calculate the Glomerular filtration rate (GFR). Urinary albumin excretion was measured by nephelometry while Copeptin and Cystatin C were measured by an immunoassay. Copeptin was analyzed with variance analysis. Association between copeptin and declination of renal function was realized with the Pearson correlation test and logistic regression analysis.

Results. Copeptin was significantly higher in patients with 4 and 5 stages in comparison with patients in stage 1-3 of renal function (ANOVA, P<0.01). Negative correlation between Copeptin levels and GFR (r= -0.452, P<0.0001) and a positive correlation between Copeptin and Cystatin C levels (r= 0.430, P=<0.0001) were found.

Conclusion. Copeptin were associated with impaired renal function in the patients with type 2 diabetes. Copeptin could be considered as a predictor of renal damage in patients with type 2 diabetes. However, more studies are necessaries to establish pathophysiological mechanisms which are involved. Copeptin may be a predictor of cardiovascular disease in this population.