Effects of an oral contraceptive (norgestimate / ethinyl estradiol) on bone mineral density in adolescent females with anorexia nervosa: a double-blind placebo-controlled study.

Abstract Purpose To evaluate the effect of an oral contraceptive (OC) on bone mineral density (BMD) in adolescent females with anorexia nervosa (AN) or eating disorder not otherwise specified (EDNOS). Methods Females 11–17 years of age with AN or EDNOS entered the study. Subjects were randomized equally to treatment with a triphasic OC containing norgestimate (NGM) 180–250 μg and ethinyl estradiol (EE) 35 μg or placebo for 13 28-day cycles. Dual energy x-ray absorptiometry scans (DXA) of the lumbosacral spine (LS) and hip were obtained at baseline and after 6 and 13 cycles. Results Demographic characteristics of the 112 subjects (NGM/EE 53; Placebo 59) who received study drug and had at least one on-treatment DXA were similar between groups for age (mean: 15 years in each group) and body mass index (mean: NGM/EE 17.9 kg/m 2 ; Placebo 17.6 kg/m 2 ). At the end of Cycle 6, there was a significant increase in the mean LS BMD in the NGM/EE group compared with placebo (.020 g/cm 2 vs. .008 g/cm 2 ; p = .021); however, at the end of Cycle 13 the mean increase in LS BMD in the NGM/EE group compared with placebo was no longer significant (.026 g/cm 2 vs. .019 g/cm 2 , p = .244). There was no significant difference in change in hip BMD between groups. The incidence of adverse events was similar between groups. Conclusions In a group of adolescent females with AN or EDNOS, treatment with a triphasic OC for 13 cycles did not have a statistically significant effect on LS or hip BMD.