[Metabolic studies under administration of oral contraceptives. A review]

Abstract

The use of oral contraceptives can produce changes in the metabolism of carbohydrates, lipids, proteins, vitamins, and minerals. Responsible for the alterations seems to be the used oestrogen- and gestagen derivative and not so much the type of the contraceptive. The most frequent findings are raised serum-glucose-, insulin-, and triglyceride levels; disturbances in protein-metabolism increase the risk of developing thrombosis and hypertonia. Little is known about the significance of oral contraceptives on the vitamin- and mineral metabolism--yet extreme deficiencies have not been observed so far. Oral contraceptives can become an extra risk factor when given to women with metabolic disturbances.

PIP: A literature review of the effect of oral contraceptive (o.c.) use on various metabolic processes is presented. Several studies show an adverse effect of o.c. use on subclinical diabetes and on patients with manifest insulin-independent diabetes. Some researchers have found a beneficial effect of o.c. use on older diabetics. It has not been determined whether the estrogen or gestagen component of o.c.s is responsible for this decrease in glucose tolerance, nor has the mechanism for this effect been discovered. Changes in various plasma protein concentrations have been observed during o.c. use, which affect the blood coagulation and the blood pressure regulation systems. The estrogen component appears to be responsible for the increase in the serum triglyceride concentration during o.c. use; the mechanism is still unknown. Some studies indicate that o.c. use causes an increase in serum cholesterol levels, which could promote gall stone formation. An increase in Vitamin A concentration has been observed during o.c. use. Riboflavin, folic acid, vitamin B 12, and ascorbic acid levels have been shown to decrease during o.c. use. A decrease in pyridoxin levels during o.c. use indicates an increased metabolism of tryptophan to nicotinic acid robosyl-5-phosphate. This would cause a decrease in serotonin production, which could be a cause of the depression experienced by some o.c. users. An increase in the plasma copper and caeruloplasmin levels during o.c. use is apparently due to the estrogen component. An increase in transferrin and the serum iron levels have been observed during o.c. use. Contradictory findings are reported concerning the plasma concentration of zinc.