OCs may partially avert anorexia-related bone loss

May 9, 2019
Renée Bacher

Although OCs do not provide total protection of bone mass, they may help limit bone loss in young patients with AN.

In young women, anorexia nervosa (AN) can lead to fractures because bone mass acquisition is highest in females during puberty and late adolescence. Oral contraceptives (OCs) may partially protect these patients from loss of bone density, according to results of a study published in Reproductive Endocrinology.

Areal bone mineral density (aBMD) was higher in patients with AN on OCs than those who did not take the contraceptives. And the longer the duration of OC use and shorter the period between AN onset and start of the contraceptives, the greater the aBMD preservation. The researchers also observed that the best bone tissue responses were seen in patients with more severe AN. 

The cross-sectional study, done at the University of Montepellier in France between 2009 and 2016, enrolled 305 women aged 14.5 to 34.9 with AN, 99 of whom were on OCs, and 121 age-matched controls, none of whom were taking medication known to affect bone metabolism. 

Patients’ standing height and body mass index (BMI) were calculated and aBMD was evaluated with dual-energy x-ray absorptiometry and bone turnover markers, with leptin evaluated concomitantly. In the women with AN who were not on OCs, aBMD at whole body and femoral neck was positively and strongly associated with BMI (P< .01 and P< .001, respectively). In the group not on OCs, however, the aBMD for whole body and femoral neck remained stable whatever the BMI (P= .70 and P= .52, respectively). 

“It is worth noting that multiple adjustments on these co-variables did not modify the differences between the groups. In addition, the evaluation of OC use in a setting of current medical practice is a strong point of this study because it reinforces the potential utility of this therapy to partially protect bone tissue in young AN patients, who are seen routinely in our clinical practice,” the report said. 

While the authors encourage the prescription of contraceptives to limit bone loss in young patients with AN, particularly in those presenting as extremely underweight, they urge clinicians not to rely solely on this treatment as it does not provide total protection of bone mass. Careful monitoring of bone mass is needed in these patients until new therapeutic approaches are developed.