Lipoprotein alterations in liver cirrhosis: a possible contribution to changes in plasma oncotic pressure and viscosity

Background/Aims: To investigate whether physicochemical alterations in plasma lipoproteins are associated with changes in plasma oncotic pressure and viscosity in liver cirrhosis. Methods: The study included 66 patients with cirrhosis (confirmed by liver biopsy) and 58 healthy volunteers. The constituents measured were: the concentration, density and composition of plasma lipoproteins; plasma oncotic pressure and viscosity; and the concentrations of albumin, total protein, haptoglobin, transferrin, immunoglobulin M and α2-macroglobulin. Results: Step-wise multiple regression analysis indicated that, in the patients with cirrhosis, plasma oncotic pressure was significantly correlated with plasma albumin+viscosity (r=+0.85; p<0.001) and with plasma total protein+the density of low density lipoprotein (r=+0.74; p<0.001). The inclusion of viscosity and the density of low density lipoprotein in the regression equations significantly improved the observed correlation between albumin and plasma oncotic pressure (r=+0.70; p<0.001). Similarly, plasma viscosity was significantly correlated with the sum of plasma total protein and cholesterol (r=+0.68; p<0.001). The inclusion of cholesterol in the regression equation significantly increased the observed correlation between total protein and plasma viscosity (r=+ 0.59; p<0.001). Conclusions: These results suggest that lipoprotein alterations associated with liver cirrhosis may play a role in determing plasma oncotic pressure and viscosity, and thus could influence the progression of the disease.