Effects of Age, Sex and Obesity on High Density Lipoprotein Cholesterol and Phospholipids in Normal Subjects and in Patients with Ischemic Heart Disease

Abstract

The hypercholesterolemia has been considered as one of the important risk factors in developing atherosclerosis.
Recent studies have demonstrated the negative correlation between the high density lipoprotein (HDL) cholesterol levels and the incidence of coronary heart disease.
The HDL contains more phospholipids than cholesterol. There are, however, not enough discussions upon HDL-phospholipids concerning clinical availabilities.
In the present study, HDL-cholesterol and HDL-phospholipids were mesured by precipitation method (Phosphotangstate-Mgcl₂) in 253 normal subjects and in 24 patients with ischemic heart disease. The relationship between HDL cholesterol and HDL phospholipids, and effects of age, sex and obesity were discussed.
The results were as follows: (1) Plasma total cholesterol, plasma total cholesterol minus HDL cholesterol (VLDL, LDL cholesterol), and VLDL, LDL cholesterol/HDL cholesterol ratio (cholesterol ratio) had significant positive correlations with aging. There was, although, no correlation between HDL cholesterol and aging. (2) HDL cholesterol levels and HDL cholesterol/HDL phospholipids ratio (HDL c/p ratio) in female were significantly higher than those of male. (3) Plasma total cholesterol, VLDL, LDL cholesterol, and cholesterol ratio had significant positive correlations with obesity index in both sexes. HDL cholesterol, HDL phospholipids, and HDL c/p ratio had significant negative correlation with obesity index in male. There was significant positive relationship between plasma triglycerides and obesity index in male. (4) The levels of HDL cholesterol and HDL-phospholipids in patients with ischemic heart disease were significantly lower than those in normal subjects in both sexes. HDL c/p ratio in patients with ischemic heart disease were significantly lower than that of normal female. (5) HDL cholesterol significantly correlated with HDL phospholipids both in normal subjects and in patients with ischemic heart disease. (6) HDL c/p ratio of female was higher than that of male.
These findings suggest that sex, obesity and presence of ischemic heart disease correlated with the levels of HDL cholesterol and cholesterol ratio as well as HDL phospholipids and HDL c/p ratio. HDL cholesterol and HDL phospholids were not influenced by aging, but cholesterol ratio and HDL c/p ratio were influenced by aging.
HDL c/p ratio in normal subjects distributed within narrow limits. In patients with ischemic heart disease, plasma, content of HDL phospholipids as well as HDL cholesterol was significantly decreased.