Studies of plasma viscosity in primary hyperlipoproteinaemia.

Using an Ubbelohde capillary viscometer, viscosity was determined in the plasma of 39 patients with a primary hyperlipoproteinaemia (type IIa, n=13; type IV, n=12; type IIb, n=14), in isolated lipoprotein fractions as well as in sera which differed only in their lipoprotein concentration. Plasma viscosity of the patients with hyperlipoproteinaemia was compared to that of a normolipidaemic control group and correlated with the lipid fractions characteristic of the different hyperlipoproteinaemia types. Plasma viscosity in types IIa, IV and IIb was found to be significantly higher than in the control group. Of the different hyperlipoproteinaemia types, IIa exhibited the lowest and IIb the highest plasma viscosity levels. The elevation of plasma viscosity was correlated with the concentration of lipoproteins (lipid fractions). In viscosity measurements of sera which varied only in lipoprotein concentrations, a correlation between the increase of viscosity and lipoprotein concentration as well as a greater efficiency of VLDL fractions was observed, similar to the viscosity results from isolated lipoproteins.