Effect of oral alanine loads on the serum triglycerides of oral contraceptive users and normal subjects.

The effect of orally administered L-alanine loads on serum triglycerides, and plasma insulin and glucose, was studied in 23 women using an estrogen-containing oral contraceptive and 13 healthy female controls. Oral contraceptive users had significantly higher fasting serum triglycerides than the controls. Serum triglycerides concentrations udnerwent little changes in the controls after alanine ingestion, whereas the oral contraceptive users showed increases which were maintained throughout the 3-hr sampling period. The two groups had similar elevations in plasma insulin after alanine loading; the glucose concentrations were unchanged. The changes in serum triglycerides may have resulted from increased metabolism of alanine to pyruvate, and its incorporation into lipids under the stimulus of elevated insulin levels.