Eating disorders and bone metabolism in women

Eating Disorders are psychiatric disorders associated with a high risk for low bone mineral density (BMD) and fractures. Low BMD is a consequence of undernutrition, changes in body composition, and hormonal alterations. This review summarizes recent findings regarding novel strategies for assessing bone outcomes in patients with eating disorders, factors contributing to altered bone metabolism, and possible therapeutic strategies.

Emerging research in this field suggests that not only anorexia nervosa, but also bulimia nervosa results in lower BMD compared to controls. To date studies of bone structure, and all randomized controlled trials examining the impact of various therapies on bone outcomes in anorexia nervosa, have focused on adolescent girls and women. We discuss the impact of anorexia nervosa on bone structure, and associations of resting energy expenditure, marrow adipose tissue (including the ratio of saturated to unsaturated fat), and cold activated brown adipose tissue with BMD and bone structure. Promising strategies for treatment include physiological estrogen replacement (rather than oral contraceptives) in adolescent girls with anorexia nervosa, and bisphosphonates, as well as teriparatide, in adult women with anorexia nervosa.

Recent data on (i) BMD and bone structure in adolescent girls and women with eating disorders, (ii) factors that contribute to altered bone metabolism, and (iii) randomized controlled trials reporting positive effects of physiologic estrogen replacement, bisphosphonates and teriparatide on bone health, provide us with a greater understanding of the impact of eating disorders on bone and novel management strategies.