Effects of Combined Oral Contraceptive Ethinylestradiol (30 μg) and Dienogest (2 mg) on Carbohydrate Metabolism During 1 Year of Conventional or Extended-Cycle Use

Abstract

The effects of extended regimens of combined oral contraceptives (COCs) on carbohydrate metabolism are largely unknown. The present study compared the effects of a COC containing 30 microg ethinylestradiol and 2 mg dienogest (EE/DNG) in conventional and extended-cycle regimen over 1 year. Parameters of carbohydrate metabolism were measured in 59 women treated with EE/DNG either conventionally (13 cycles of 21+7 days) or in extended-cycle regimen (4 cycles of 84+7 days). Blood samples were taken in a control cycle, and at 3 and 12 months of treatment. The mean levels of HbA1c and fasting glucose levels remained stable in both conventional and extended-regimen of EE/DNG. The mean levels of fasting insulin and C-peptide underwent comparable increases in both regimens, suggesting a similar readjustment of glucose metabolism via slightly increased insulin secretion. For both regimens, the response to the oral glucose tolerance test (OGTT) showed a slightly impaired glucose tolerance and insulin resistance at 3 months. These changes improved or returned to baseline at 12 months. Accordingly, the mean index for insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR) increased and the mean insulin sensitivity index [ISI (composite)] decreased modestly in both groups. The present study demonstrates that there are no statistically significant differences between the effects of conventional and extended-cycle treatment on carbohydrate metabolism over 1 year of treatment. In general, the effects of both regimens were moderate and mostly transient.

Continuous use of oral contraceptives: an overview of effects and side‐effects

“…This may indicate that there is an increased coagulation activity for both continuous and conventional OCs but no difference between the two regimens. Two RCTs (44,46) demonstrated no change between the groups in fasting glucose or insulin level from baseline to end of study.…”

“…OCs administered cyclically are known to affect the coagulation system by increasing the hepatic production of several coagulation factors. Furthermore, OCs affect the metabolic parameters, including lipids and carbohydrates, in a negative way (46).…”

Ethinyl estradiol vs estradiol valerate in combined oral contraceptives – Effect on glucose tolerance: A randomized, controlled clinical trial

“…Regarding the effects of COCs containing EE on glucose metabolism, results remain conflicting, although a tendency towards worsened insulin sensitivity has been reported [30].…”