The Effects on Carbohydrate Metabolism of a 21-day Monophasic Oral Contraceptive Containing Levonorgestrel 100 mcg and Ethinyl Estradiol 20 mcg

Abstract

After treatment with high dose oral contraceptives, alterations in carbohydrate metabolism including decreased glucose tolerance and increased insulin resistance have been described. The purpose of this study was to determine the effects of a monophase oral contraceptive preparation of levonorgestrel 100 mcg and ethinyl estradiol 20 mcg (LNG/EE 100/20) on carbohydrate metabolism. LNG/EE 100/20 was administered orally once daily for 21 days followed by placebo for 7 days. Glucose tolerance was evaluated with the use of a standard 3-hour glucose tolerance test (GTT after administration of a 75-g loading dose of glucose. The GTT was performed dUring the prestudy period between menstrual cycle days 17 and 26. Testing was repeated during the third and sixth treatment cycles between tablet days 15 and 21. Mean changes from baseline values in glucose and insulin were calculated for each collection time. Forty healthy women were enrolled at a single university outpatient center. Data were available for analysis for 15 subjects who had complete data through 6 cycles. Two subjects with abnormally high pretreatment insulin values were excluded from the analysis. Except for a small mean increase in the 30-minute glucose value at cycle 6, there were no statistically significant changes from baseline in glucose or insulin values for the remaining 13 subjects. These changes were not believed to be clinically important because all individual values remained within the normal range. The results of this study show that this preparation of LNG/EE 100/20 has no clinically important effects on carbohydrate metabolism.