Intravenous Glucose Tolerance, Insulin Response, Fasting Blood Glucose and Serum Insulin During Short‐Term Administration of a Combined Oral Contraceptive

A series of 25 healthy women, 13 of whom had a tendency to diabetes, was studied for 5 consecutive menstrual cycles, with regard to the effect of a combined oral contraceptive containing O.S mg norgestrel and 0.05 mg ethinylestradiol (Eugynon®) on the carbohydrate metabolism. The following tests were performed on these women at midcycle in the cycle prior to, in the two cycles during, and in the second cycle after administration of the drug: Fasting blood sugar, i.v. glucose‐tolerance, fasting insulin and insulin response to i.v. glucose injection. The drug was administered daily from the fifth to twenty‐fifth day of cycles two and three. Thus each subject served as her own control. The statistical analysis of the results showed no alteration in the fasting blood sugar or difference between those with a diabetic tendency and those without. Glucose assimilation was significantly improved during the second cycle of administration and the follow‐up cycle, this was not dependent on the tendency to diabetes. The women with a tendency to diabetes had a significantly slower assimilation than those with no such tendency. However, this difference remained constant throughout the period under study. The results of the fasting insulin test remained unchanged during the investigation, no difference was seen between the two groups of women, those with the tendency to the disease and those without. The insulin response test showed slightly higher values during the two cycles of administration, this increase was significant, and was seen to occur in both groups. The women with a diabetic tendency had slightly higher values in the insulin response test than those of the women belonging to the other group, the difference was not significant except in the second cycle of drug intake.