[The role of anorexia nervosa in secondary osteoporosis development with the risk for low energy fractures].

Anorexia nervosa (AN) has in recent years become considerably more common. The disease primarily affects girls and young women, also boys and young men. AN is a risk factor for secondary osteoporosis. AN-related metabolic disturbances lead to diminished bone quality and increased risk of fractures. The consequences of low energy fractures are the main causes of death in women with AN. Hormonal disturbances (e.g. hypoestrogenism, increased levels of ghrelin and Y peptide, changes in leptin and endocannabinoid levels), as well as the mechanisms involved in bone resorption (RANK/RANKL/OPG system), are considered to be of great importance for anorectic bone quality. The risk for osteoporotic, non-vertebral fractures in AN patients is significantly higher than in healthy women. Improvement of bone mineral density is possible after substantial body mass increase. Weight loss, in conjunction with a well-balanced, controlled diet, is the key to correct peak bone mass levels, and diminishes the risk for osteoporosis with its consequence of low energy bone fractures.