title: Endocrinology of anorexia nervosa in young people: recent insights.
abstract: OBJECTIVE
  Anorexia nervosa is among the most prevalent chronic medical conditions in young adults. It has acute as well as long-term consequences, some of which, such as low bone mineral density (BMD), are not completely reversible even after weight restoration. This review discusses our current understanding of endocrine consequences of anorexia nervosa.
  
  
  RESULTS
  Anorexia nervosa is characterized by changes in multiple neuroendocrine axes including acquired hypogonadotropic hypogonadism, growth hormone resistance with low insulin-like growth factor-1 (likely mediated by fibroblast growth factor-1), relative hypercortisolemia, alterations in adipokines such as leptin, adiponectin and resistin, and gut peptides including ghrelin, PYY and amylin. These changes in turn contribute to low BMD. Studies in anorexia nervosa have demonstrated abnormalities in bone microarchitecture and strength, and an association between increased marrow fat and decreased BMD. One study in adolescents reported an improvement in BMD following physiologic estrogen replacement, and another in adults demonstrated improved BMD following risedronate administration. Brown adipose tissue is reduced in anorexia nervosa, consistent with an adaptive response to the energy deficit state.
  
  
  CONCLUSIONS
  Anorexia nervosa is associated with widespread physiologic adaptations to the underlying state of undernutrition. Hormonal changes in anorexia nervosa affect BMD adversely. Further investigation is underway to optimize therapeutic strategies for low BMD.
authors.affiliation: aPediatric Endocrine bNeuroendocrine Units of Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Vibha
authors.initials: V
authors.lastname: Singhal
authors.forename: Madhusmita
authors.initials: M
authors.lastname: Misra
authors.forename: Anne
authors.initials: A
authors.lastname: Klibanski
mesh_terms: D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000293:Adolescent; D000856:Anorexia Nervosa / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D015519:Bone Density; D001853:Bone Marrow / Q000378:metabolism*; D004704:Endocrinology; D004734:Energy Metabolism; D015914:Estrogen Replacement Therapy / Q000379:methods; D005260:Female; D019382:Human Growth Hormone / Q000378:metabolism; D006801:Humans; D007006:Hypogonadism / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D008297:Male; D010913:Pituitary-Adrenal System / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D019382:Human Growth Hormone