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 (ISOGTT) was found in women on PILL therapy compared to those in the RING group (p<.035). Pancreatic β-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.