Effect of carnitine on serum HDL-cholesterol: report of two cases.

In two otherwise normal male subjects selected for normal serum cholesterol and triglycerides but low serum high-density lipoprotein (HDL) levels, oral administration of 1 g per day of L-carnitine over a period of 10-15 weeks caused a substantial increase in high-density lipoprotein levels, as well as a decrease in serum triglycerides. The ratio of HDL-cholesterol to total cholesterol increased, but this change was not due to an obligatory lowering of total cholesterol. Possible mechanisms of the carnitine effect are discussed. Since elevated high-density lipoprotein levels significantly reduce the risk of arteriosclerotic cardiovascular disease, this action of carnitine deserves further study.