Carbohydrate metabolic studies during twelve months of treatment with a low-dose combination oral contraceptive

Carbohydrate metabolism was evaluated in twenty healthy women volunteers using a low-dose combination oral contraceptive (OC) containing 30 micrograms of ethinyl estradiol and 500 micrograms of dl-norgestrel by measurement of serum glucose and insulin levels during 3-hour oral glucose tolerance test (OGTT) before and after 3, 6 and 12 months of medication. There were no significant differences in body weight or blood pressure between pretreatment and posttreatment. Fasting serum glucose levels were slightly reduced, though not significantly, during all periods of treatment. But serum glucose levels were increased at 1, 2 and 3 hours in association with high insulin responses during OGTT in all periods of OC therapy, indicating mild to moderate insulin resistance. These data suggest that the low-dose combination OC used in the study exerts alterations on carbohydrate metabolism in women during one year of OC use.