Contraceptive vaginal ring use for women has less adverse metabolic effects than an oral contraceptive

This study compared metabolic, hormonal and lipid profiles before and during use of a contraceptive vaginal ring (RING) releasing 15 mcg ethinyl estradiol (EE) and 120 mcg etonogestrel per day NuvaRing, Organon USA Inc., Roseland, NJ versus a low-dose oral contraceptive (PILL) containing 20 mcg EE and 100 mcg levonorgestrel daily (Aviane, Barr Pharmaceuticals Inc., Pomona, NY).

Sixty-five women were randomized to either the RING or PILL treatment for five cycles. In the pretreatment cycle (Cycle Days 2-5) and during Weeks 2 and 3 of the fifth treatment cycle, a 75-g oral glucose tolerance test (OGTT) was performed. Baseline samples were used to evaluate basal hormonal, metabolic and lipid levels.

Forty-two women completed the study. Basal insulin resistance (HOMA-IR) was slightly decreased, whereas a significant reduction in the insulin sensitivity index (IS(OGTT)) was found in women on PILL therapy compared to those in the RING group (p<.035). Pancreatic beta-cell function was not significantly altered with either treatment.

The lower-dose, nonoral hormonal RING had a lesser impact on carbohydrate metabolism and greater reduction of free androgen and dehydroepiandrosterone sulfate levels than PILL treatment.