High density lipoprotein and other lipoproteins in normolipidaemic and hypertriglyceridaemic (type IV) men with coronary artery disease.

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.