Studies in asymptomatic primary hyperlipidaemia. V. Peripheral circulation.

The occurrence of early signs of peripheral vascular disease (PVD) of the lower limbs has been studied with digital pulse plethysmography in 160 men and 123 women above the age of 35, who were all subjectively healthy but were found to have primary hyperlipoproteinaemia (HLP) at a health control centre. Quantitative analysis of serum lipoproteins with cholesterol and triglyceride (TG) determination of each of the very low (VLDL), low (LDL) and high (HDL) density lipoprotein clases together with lipoprotein paper electrophoresis was performed. Identical investigations were performed on control subjects with non-elevated serum lipids. Inclination time (IT) was substantially prolonged in 12% of HLP males and 7% of HLP females. The frequency of male subjects with prolonged IT was lower when only LDL was elevated (type IIA) than in the other types of HLP. The subjects with prolonged IT had three characteristic features. 1) Moderate elevations of both serum cholesterol and TG. These elevations occurred often in both VLDL and LDL lipoprotein classes. IT prolongations were not seen when VLDL or LDL lipoproteins were singly maredly elevated. 2) High frequency of smokers. 3) Most of the subjects were above the age of 50. The results suggest that the most atherogenic lipoprotein abnormalities to the arteries of the lower limb are on the one hand the relatively TG-rich part of the LDL (LDL1) fraction and on the other hand the relatively cholesterol-rich part of the VLDL fraction. Furthermore the results stress the deleterious influence of smoking even in the preclinical stage of PVD.