Bone mineral density in women aged 40-49 years using depot-medroxyprogesterone acetate, norethisterone enanthate or combined oral contraceptives for contraception

There was no significant difference in BMD between the four contraceptive user groups (p=.26) with and without adjustment for age. Although a small decrease in BMD was noted in the age range of 40-49 years, this was not statistically significant (p=.7). The BMD was found to be significantly associated with body mass index (BMI) (p≤.0001) at both measurement sites, with an increase of one unit of BMI translating to an increase of 0.0044 g/cm2 in radius BMD. Follicle-stimulating hormone (FSH) level ≥25.8 mIU/mL was associated with a decrease of 0.017 g/cm2 in radius BMD relative to women with FSH <25.8 mIU/mL. Significant interaction between FSH and BMI in their effect on BMD was observed (p=.006). This study found no evidence that long-term use of DMPA, NET-EN and COCs affects BMD in this population.