Prospective carbohydrate metabolism studies in women using a low-estrogen oral contraceptive for one year.

Three-hour oral glucose tolerance tests were done before and after one year of use of a low-estrogen-type oral contraceptive (OC) in 14 women. The drug contained 0.035 mg ethinyl estradiol and 0.4 mg norethindrone. Both blood glucose and plasma insulin were measured. During the year there were no significant changes in the subjects' weights, whereas their blood pressures decreased. The results showed a significance decrease in the fasting blood glucose level after one year for women with a "normal" control test while the remainder of the values remained unchanged. For women with a "borderline" abnormal control test there was a significant decrease in the two-hour glucose level. There were no significant changes in the plasma insulin levels. These results confirm that this low-estrogen-type oral contraceptive produces minimal changes in the carbohydrate metabolism of users.