Objective: In this study, we aimed to investigate the alterations in plasma viscosity and whether there was a relationship between plasma viscosity and endothelial dysfunction markers such as nitric oxide (NOx), asymmetric dimethylarginine (ADMA) and oxidized Low Density Lipoprotein (oxLDL) in dyslipidemic subjects.
Material and method: 35 subjects with normolipidemia and 30 subjects with hyperlipidemia were involved in this study. Dyslipidemia was defined as total cholesterol levels ≥200 mg/dL and/or triglyceride level ≥150 mg/dL. Plasma total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, total protein, albumin levels and NOx were determined by enzymatic methods using commercial kits. Plasma ADMA concentrations and serum levels of total oxLDL were determined by ELISA. Plasma viscosity was measured by Harkness capillary viscometer.
Result: Plasma viscosity, ADMA and oxLDL values were significantly higher in subjects with dyslipidemia than in subjects with normolipidemia. Plasma NOx concentration was decreased in dyslipidemic subjects compared to the normo-lipidemic subjects. We found that fibrinogen had no effect upon plasma viscosity in selected patients with dyslipidemia.
Conclusion: Our results demonstrated that the rheological impairment of dyslipidemic patients was related with endothelial dysfunction and this was a possible cause of both micro and macrovascular complications. Therefore, as plasma viscosity is also a sensitive parameter, it can add useful information about the diagnosis and treatment of various disorders, and it should be utilized more frequently in clinical medicine.
Keywords: Atherosclerosis; Oxidized LDL; asymmetric dimethylarginine; nitric oxide; plasma viscosity; shear stress.