title: Alteration in serum klotho levels in anorexia nervosa patients.
abstract: Klotho is a trans-membrane protein which can be shed to act as a hormone; its blood levels may be regulated by the GH/IGF-1 axis. Klotho deficient mice exhibit short lifespan and characteristics of aging and malnutrition, including decreased fat and muscle mass, osteopenia, and impaired fertility. As anorexia nervosa (AN) is characterized by malnutrition and GH resistance, we hypothesized klotho levels would be altered in AN, and aimed to assess klotho levels in undernourished AN patients and changes in klotho following weight rehabilitation.
  
  
  
  19 adolescent female AN inpatients (aged 16.1 ± 1.8 years) admitted to an inpatient service for eating disorders in a tertiary center were recruited. Blood samples were obtained on admission and after weight restoration (interval 4.0 ± 2.3 months) and analyzed for klotho, IGF-1, calcium, phosphorus, and alkaline phosphatase.
  
  
  
  Klotho levels on admission were lower than expected for age, and correlated with lumbar spine BMD Z-score (r = -0.81, p < 0.001) and alkaline phosphatase levels (r = 0.66, p = 0.003) but not with age, height-SDS, weight-SDS, BMI-SDS, or serum calcium, phosphorus and IGF-1 levels. Both IGF-1 and klotho levels increased significantly during hospitalization (IGF-1: 44 ± 17 nmol/l to 53 ± 11 nmol/l, p = 0.008; klotho: 1061 ± 421 pg/ml to 1519 ± 781 pg/ml, p = 0.008).
  
  
  
  Klotho levels are low in the acute stage of AN and increase with nutritional rehabilitation. Low klotho on admission may be secondary to low IGF-1 levels and may contribute to the clinical manifestations of AN. The role of klotho in the pathophysiology of AN and as a novel marker of disease severity should be further explored.
authors.affiliation: Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ido
authors.initials: I
authors.lastname: Wolf
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Pediatric Psychosomatic Department, The Edmond and Lily Safra Children's Hospital, The Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel.
authors.forename: Daniel
authors.initials: D
authors.lastname: Stein
authors.affiliation: Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Shiri
authors.initials: S
authors.lastname: Shahmoon
authors.affiliation: Pediatric Psychosomatic Department, The Edmond and Lily Safra Children's Hospital, The Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel.
authors.forename: Shimrit Ilana
authors.initials: SI
authors.lastname: Ziv
authors.affiliation: Institute of Endocrinology, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel.
authors.forename: Rina
authors.initials: R
authors.lastname: Hemi
authors.affiliation: Institute of Endocrinology, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel.
authors.forename: Hannah
authors.initials: H
authors.lastname: Kanety
authors.affiliation: Institute of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Tami
authors.initials: T
authors.lastname: Rubinek
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel. Electronic address: dmodan@sheba.health.gov.il.
authors.forename: Dalit
authors.initials: D
authors.lastname: Modan-Moses
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D000856:Anorexia Nervosa / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D015519:Bone Density; D002118:Calcium / Q000097:blood; D002648:Child; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007557:Israel; D000090265:Klotho Proteins; D008565:Membrane Proteins / Q000097:blood*; D010758:Phosphorus / Q000097:blood
chemical_list: D015415:Biomarkers; C538995:KLB protein, human; D008565:Membrane Proteins; D010758:Phosphorus; D007334:Insulin-Like Growth Factor I; D000469:Alkaline Phosphatase; D000090265:Klotho Proteins; D002118:Calcium
keywords: Adipocytes; Anorexia nervosa; IGF-1; Klotho; Malnutrition; Osteoporosis