Mechanisms Underlying Hypercholesterolemia and Hypertriglyceridemia

¹ Los Angeles, California

This article points out that an increased serum cholesterol, other than in hypothyroidism, results from two main causes: 1. A primary rise in cholesterol unrelated to any serum triglyceride abnormality, essential hypercholesterolemia; 2. A primary rise in serum triglycerides with the elevation in cholesterol a secondary physico-chemical effect.

The cause of essential hypercholesterolemia is unknown, and strict limitation of dietary cholesterol intake is only partially effective since endogenous cholesterol synthesis is elevated. The cause of elevated serum triglycerides apparently lies in the defective removal of exogenous or endogenously synthesized triglycerides from the bloodstream. The central role of the enzymatic heparin lipemia-clearing factor, lipoprotein lipase, in fat clearing, and the evidence available from a variety of studies, indicate that interference with this mechanism is the main cause of abnormally high serum triglycerides. Since endogenous triglycerides can be synthesized from fats or carbohydrates, it is apparent that the limitation of dietary fats will not reduce the serum triglycerides and cholesterol in all cases.