What is the relationship between eating disorders and osteoporosis?
Eating disorders--anorexia nervosa, bulimia nervosa, and binge eating--are common in young women in the United States, with an estimated prevalence of 1 to 4 percent. Of these eating disorders, anorexia has the most profound effect on bone health (1). Bulimia and binge eating without anorexic features have not been shown to be associated with bone loss.
More than 50 percent of women with anorexia nervosa have been shown to have bone loss greater than two standard deviations than that of healthy age-matched controls (2). One study of 130 women in the community with anorexia nervosa found that 92% had significant bone loss (> 1 SD) and 38% had severe bone loss (>2.5 SD) at one or more skeletal sites as compared to WHO organization criteria (3). Fracture risk doubles with each decrease of 1 SD in BMD (4).
The cause of bone loss in anorexia nervosa is not clearly understood. PatientsSome studies have suggested that patients with anorexia nervosa have both increased osteoclast function (bone resorption) and decreased osteoblast function (bone formation )which may be due to low estrogen and IGF-I concentrations, in additional to other factors related to poor nutritional status(5, 6).
- Anderson AE, Woodward PJ, LaFrance N. Bone mineral density of eating disorder subgroups. International Journal of Eating Disorders 1995; 18: 335-342.
- Biller BM, Saxe V, Herzog DB, Rosenthal DI, and Klibanski A. Mechanisms of Osteoporosis in adult and adolescent women with anorexia nervosa. Journal of Clinical Endocrinology and Metabolism 1989; 68: 548-554.
- Grinspoon S, Thomas E, Pitts S, Gross E, et al. Prevalence and Predictive factors for regional osteopenia in women with anorexia nervosa. Ann Int Med 2000; 133: 790-94.
- Cummings SR, Black DM, Nevitt MC, Browner W, et al. Bone density at various sites for prediction of hip fractures.. The Study of Oteoporotic Fractures Research Group. Lancet 1993; 341: 72-75.
- Grinspoon, S, Miller K, Coyle C et al. Severity of osteopenia in estrogen-deficient women with anorexia nervosa and hypothalamic amenorrhea. Journal of Clinical Endocrinology and Metabolism 1999; 84: 2049-2055. Available online.
- Dominguez J, Goodman L, Gupta SS, et al. Treatment of anorexia nervosa is associated with increases in bone mineral density, and recovery is a biphasic process involving both nutrition and return of menses. American Journal of Clinical Nutrition 2007; 86: 92-99.