Carbohydrate metabolism studies in women using Brevicon, a low-estrogen type of oral contraceptive, for one year.

A prospective study of carbohydrate metabolism was done in 12 normal women over 1 year's time while they were using the low-estrogen type of oral contraceptive Brevicon, which contains 0.035 mg of ethinyl estradiol and 0.5 mg of norethindrone. The women had a 3-hour oral glucose tolerance test before starting the drug and then in 12 months, both blood glucose and plasma insulin levels were measured. After 1 year, there was no significant change in weight, blood pressure, or plasma insulin levels. There was a slight decrease in the fasting blood glucose value after 1 year's use (67.5 +/- 1.5 versus 63.2 +/- 1.3 mg/dl). The other glucose values were unchanged. The importance of these data in terms of mechanisms of action of the steroids on metabolism and the safety of oral contraceptive usage is discussed.