摘要:The complications, especially those affecting microcirculation, exhibit great importance in the assessment and follow-up of patients with diabetes mellitus. Blood viscosity plays its most important role in the microcirculation where it contributes significantly to peripheral resistance and may cause sludging in the post capillary venules. The effect of whole blood viscosity in patients whit diabetic nephropaty is still unclear. The aim of this study was to examine the influence of glicaemic control measured by glicated hemoglobin on rheological parameters, and especially on whole blood and plasma viscosity in patients with diabetic nephropaty. Blood viscosity is an important determinant of local flow characteristics. Blood exhibits shear thinning behavior: its viscosity decreases exponentially with increasing shear rates. Estimation of whole blood and plasma viscosity was made on 42 patients, comparing different stages of diabetic nephropathy and with different values of glicated hemoglobin. Depression of the regulatory mechanisms of microvascular blood flow as well as decreased tissue perfusion indicated the restricted blood flow in microcirculatory network in diabetic nephropathy. In conclusion blood viscosity was elevated in the patients with major organ complications and not in the patients without or with early complications, in correlation with poor glicaemic control.