SERUM β-LIPOPROTEIN LEVELS IN HEALTH AND DISEASE, AS DETERMINED BY THE NEPHELOMETRIC METHOD WITH AMYLOPECTIN SULFATE AS REAGENT *

Abstract

Serum [beta]-lipoprotein was determined in over 2,000 individuals by the nephelometric method with amylopectin sulfate as reagent. A method for the standardization of the reagent was devised, based on the determination of its sulfur content and of the turbidity formed by the addition of barium ions to amylopectin sulfate in an acid medium. Among all polyanions, amylopectin sulfate is best suited because its molecular weight is easily controllable. A normal population of 942 individuals ranging from 25 to 70 years of age exhibited a mean [beta]-lipoprotein value of 678 mg% (standard deviation 158). In 763 individuals with arteriosclerosis, including 358 with cardiovascular disease, 307 with cerebrovascular disease, and 63 with the simultaneous occurrence of these two conditions, the mean lipoprotein level was elevated to 788 mg%. This increase is highly significant (t = 12.75). Increases in the concentrations of serum [beta]-lipoprotein have also been observed in kidney and in liver diseases, in diabetes and in hypercholesterolemia. No significant changes in serum [beta]-lipoprotein were found in malignant diseases or in limited numbers of patients with anemia, arthritis, neurological diseases, or obesity. The correlation between total serum cholesterol and nephelometric [beta]-lipoprotein is low; it is somewhat higher in patients with hypercholesterolemia.