Plasma-triglycerides in regulation of H.D.L.-cholesterol levels.

Plasma-high-density-lipoprotein (H.D.L.) cholesterol concentrations are lower in patients with coronary-artery disease than in control subjects. In an investigation of the relationship of H.D.L. cholesterol to other lipid and lipoprotein parameters in normal and hyperlipoproteinaemic subjects inverse correlations were found between H.D.L. cholesterol and very-low-density-lipoprotein (V.L.D.L.) cholesterol, and between H.D.L. cholesterol and plasma-triglyceride levels. Mean H.D.L.-cholesterol concentrations in normal subjects were 50 mg/dl, and in hyperlipoproteinaemic patients they were: type I, 17 mg/dl; type II, 44 mg/dl; type III, 38 mg/dl; type IV, 37 mg/dl; and type V, 27 mg/dl. H.D.L.-cholesterol levels were lowest in patients with fasting chylomicronaemia and were diminished in hypertriglyceridaemic subjects, suggesting a relationship between the metabolism of triglyceride-rich lipoproteins and H.D.L.