Implanon use lowers plasma concentrations of high-molecular-weight adiponectin

To investigate the effect of the low-dosed etonogestrel-releasing contraceptive implant Implanon on new cardiovascular risk markers, we studied the effect of this implant on adiponectin and its metabolically important isomer high-molecular-weight adiponectin (HMW). Low-dosed progestagen-only contraception is preferentially prescribed to females with increased cardiovascular risks.

Longitudinal study.

Family-planning center of a university hospital.

Forty healthy nonsmoking women with regular cycles (n=20 controls without hormonal contraception; n=20 cases wishing the insertion of Implanon).

Blood samples for the measurements of adiponectin, HMW, C-reactive protein (CRP), sex hormone binding globulin, sexual hormones, and plasma lipids were taken in the early follicular phase of the cycle in both groups. A second sample was taken 12 weeks after Implanon insertion or in the controls during the early follicular phase of cycle four.

At baseline there was a significant correlation between adiponectin and the parameters hsCRP and high-density lipoprotein. Implanon treatment caused a significant decrease in HMW and the HMW/adiponectin ratio. Additionally plasma lipids (cholesterol, high-density lipoprotein, low-density lipoprotein), sex hormone binding globulin, and testosterone levels decreased significantly. Adiponectin plasma concentrations were not affected.

Short-term Implanon use in healthy premenopausal women was associated with a decrease in the cardioprotective adiponectin isomer HMW. It remains to be investigated if this decrease persists after longer use of the implant.