An exploratory study on the association of lifestyle factors with serum etonogestrel concentrations among contraceptive implant users.

ABSTRACT

PURPOSE: To explore how diet and exercise habits associate with serum etonogestrel concentrations among contraceptive implant users. MATERIALS AND METHODS: We conducted a secondary analysis of healthy, reproductive-age women using etonogestrel implants. This study was registered on ClinicalTrials.gov, NCT03092037. We assessed diet and exercise habits with two validated surveys Healthy Eating Vital Signs and the Stanford Brief Activity Survey. Participants previously had their serum etonogestrel concentrations measured using a validated liquid-chromatography mass-spectrometry assay. We then used linear modelling to test for associations between survey responses and serum etonogestrel concentrations. RESULTS: Among 129 participants, diet and exercise habits had no significant associations with serum etonogestrel concentrations (p = 0.22-0.72), with inconsistent effects found for increased caloric intake and sedentary lifestyle. CONCLUSION: This exploratory study found no significant effect of diet or exercise habits on steady-state pharmacokinetics among contraceptive implant users. CLINICAL TRIAL REGISTRATION Clinicaltrials.gov NCT03092037.