Lipid composition of serum lipoproteins in patients with primary type IIb and type IV hyperlipoproteinemia.

Cholesterol, triglyceride and phospholipid concentrations of VLDL, LDL and HDL were studied in 20 patients with primary type IIb, 25 patients with primary type IV and in 18 controls. Both types are not only characterized by different concentrations of lipoprotein lipids, but also by their different lipid composition. Type IIb had more triglycerides in the LDL, type IV in the LDL and HDL. The HDL cholesterol content of type IV was decreased. The percent phospholipid concentration of HDL was identical in the 3 groups, demonstrating the constant role of this lipid fraction. The lipid relationships between the lipoproteins showed that the LDL/HDL lipid ratio of type IIb exceeded type IV ratio in spite of normal HDL lipid concentration in type IIb.