No abstract

The aim was to investigate whether a low concentration of high density lipoprotein (HDL) may be used as a risk indicator in normolipidaemic (n.l.) subjects, and whether a reduced HDL concentration constitutes an additional risk factor in hyperlipoproteinaemia. Eighty-two men with angiographically documented coronary artery disease (CAD) were studied. The majority of the CAD men was either n.l. (n = 38) or had type IV hyperlipoproteinaemia (n = 22). These two groups were compared separately to one group of healthy n.l. subjects (n = 44), and one group of healthy subjects with type IV hyperlipoproteinaemia (n = 29). In about 50% of n.l. CAD men the HDL-cholesterol (HDL-C) was lower than the 15th percentile (0.90 mmol/l) of n.l. controls, and about 65% of n.l. CAD men had ratios of HDL-C/total plasma cholesterol (C) lower than 0.17, the 15th percentile of n.l. controls. Almost all type IV subjects had reduced HDL-C levels and decreased ratios of HDL-C/C, whether they had obvious CAD or not. Thus, in normolipidaemia, but not in type IV hyperlipoproteinaemia, a low HDL-C level may be used as an additional risk factor for CAD development.

The purpose of this study was to investigate sexual differences regarding lipoprotein concentrations and compositions, and the cholesterol esterification rate in subjects with type IIa hypercholesterolaemia. Twenty men and 33 women with type IIa hyperlipoproteinaemia, asymptomatic as regards ischaemic heart disease were investigated. Total cholesterol (TC), triglycerides (TG) and phospholipids (PL) were measured in plasma and in the very-low-density (VLDL), low-density (LDL) and high-density lipoprotein (HDL) fractions. The cholesterol esterification rate was determined in plasma in vitro. In comparison with the male group the females had higher concentrations of TC and PL in the HDL, leading to higher ratios of HDL-TC/LDL-TC and HDL-PL/LDL-Pl in the females group. The cholesterol esterification rates were equal in the sexes. However, relations between the cholesterol esterification rates and lipoprotein concentrations and between cholesterol esterification rates and overweight were not equal in the sexes. The higher HDL-TC concentration and HDL-TC/DL-TC ratio in women than in men with type IIa might partly explain the lower female morbidity in cardiovascular disease.