Studies on the Lipid Metabolism in Arteriosclerosis

Relationship between Hyperlipemia and Plasma Fatty Acid

Abstract

Introduction;
It has been commonly recognized that both hyperlipemia and the abnormality of the plasma fatty acid composition are present in arteriosclerotic patients.
The question now arises which one or both of them may play the important role in the development of arteriosclerosis.
In normal and arteriosclerotic subjects the plasma concentrations of various lipids, low density lipoproteins and fatty acids, and the plasma fatty acid composition were determined to study the relationship between hyperlipemia and plasma fatty acid in arteriosclerosis.
Methods;
Thirty-four male patients with arteriosclerosis and 33 controls, (aged 40-60 years), were examined. Venous blood samples were drawn in the morning after an overnight fast. In these samples the plasma concentrations of total lipids, total cholesterol, phospholipids, triglycerides, total fatty acids, each of the fatty acids and low density Sf_0-12, Sf_12-400 lipoprotein besides the plasma fatty acid composition were determined for comparision between each other.
Results;
1) The increase in the plasma concentrations of low density lipoproteins and other lipids except phospholipids was observed in arteriosclerotic subjects.
2) In the plasma fatty acid composition, the increase in the proportions of palmitic acid and oleic acid and the decrease in the proportion of linoleic acid were shown in arteriosclerotic patients. The increase of other fatty acids levels except some essential fatty acids such as linoleic acid and arachidonic acid was shown in the same patients.
3) Each positive relationship was found between total fatty acids levels and various lipids levels. Each positive relationship between various fatty acids levels was also observed in normal subjects, but no relationship between linoleic acid and oleic acid levels was observed in arteriosclerotic subjects.
4) The relationships between various lipids levels and fatty acids levels were found according to the fatty acid-selectivity of lipids in normal subjects.
However, no significant relationship was observed between them in arteriosclerotic subjects.
5) No relationship between lipids levels and fatty acids percentages was observed in both groups.
6) The relationships between Sf_0-12 lipoprotein levels and linoleic acid levels; between Sf_12-400 lipoprotein levels and palmitic acid levels; between Sf_12-400 lipoprotein levels and palmitoleic acid levels; between Sf_12-400 lipoprotein levels and oleic acid levels, were observed in normal subjects.
However, no relationship between low density lipoproteins levels and fatty acids levels was observed in arteriosclerotic subjects.
7) No relationship between low density lipoproteins levels and fatty acids percentages was observed in both groups.
Summary;
These results indicate that the change of plasma fatty acid composition in arteriosclerotic patients was not due to the plasma concentrations of essential fatty acids, but due to the increase of the plasma concentrations of other fatty acids except for them, and that the fatty acid-selectivity of each plasma lipid seems to be in order in normal subjects, but to be in disorder in arteriosclerotic subjects.
It is therefore suggested that the hyperlipemia may have the primary importance in the development of arteriosclerosis, and the change of the plasma fatty acid composition may have atherogenesity through the persistence of hyperlipemia.