Metabolic effects of progesterone.

Progesterone has important effects on carbohydrate, lipid and protein metabolism. This steroid induces hyperinsulinemia, possibly by direct action on pancreatic islets, while promoting glycogen storage in the liver. Paradoxically, it antagonizes the effects of insulin on glucose metabolism in adipose tissue and skeletal muscle. Progesterone stimulates deposition of body fat but had catabolic effects on protein metabolism. Provisional evidence is offered that the steroid may influence ketone body production by the liver as well. When these steroid actions are considered together, their most relevant expression appears to be the physiologic changes observed during normal pregnancy.