Lipoprotein Composition and Lipoprotein Interrelations in 50-year-old Men with Hyperlipoproteinaemia

Abstract

The serum lipoprotein (LP) composition and LP lipid interrelations were studied in 50-year-old men with different types of hyperlipoproteinaemia (HLP) and in randomly sampled healthy controls from the same population.

The ratio cholesterol/triglycerides in very low density lipoproteins (VLDL) was high in HLP type III. The other types of HLP showed ratios not significantly different from the controls. The low density lipoprotein (LDL) cholesterol concentration was similar in controls, type III and type IV while, by definition, higher values were seen in type IIA and IIB. All types of HLP showed statistically significantly higher LDL triglycerides than the controls. HLP type HA and IIB showed cholesterol/triglyceride ratios in LDL similar to the controls. The corresponding ratio in type IV was lower than in the control subjects but the lowest ratio was seen in type III with a mean value below the 5th percentile of healthy controls.

The high density lipoprotein (HDL) cholesterol concentration was decreased in HLP type IV. Apparently elevated HDL triglyceride levels were seen in all types of HLP with the highest mean value in type III.

The LP lipid interclass relationships were analysed in the random sample of healthy men and compared to corresponding relationships in the different types of HLP. Apart from HLP type HI and HLP type IV with low LDL cholesterol levels all other types of LP patterns seemed to conform to a common model of LP interconversions. In type IV a significant negative correlation between VLDL concentration and LDL cholesterol levels was demonstrated in subjects with low LDL cholesterol as well as a direct relationship between LDL cholesterol concentration and the cholesterol/triglyceride ratio in VLDL. There were no significant correlations between LDL cholesterol concentration and VLDL lipid variables in other types of HLP and normolipidaemia.