title: Circulating Levels of Irisin in Hypopituitary and Normal Subjects.
abstract: BACKGROUND
  The recently identified myokine irisin conveys some of the benefits of exercise. Hypopituitarism with adult growth hormone deficiency (HP) is a situation characterized by decreased GH secretion and an altered body composition.
  
  
  OBJECTIVE
  Our aim was to study the skeletal muscle hormone irisin in HP, and compare the results with a similar group of normal subjects.
  
  
  METHODS
  Seventeen HP patients and fifty-one normal subjects of similar age and sex were studied. The diagnosis of GH deficiency was confirmed by the presence of pituitary disease and a peak GH secretion below 3 μg/L after an insulin tolerance test. The patients were adequately treated for all pituitary hormone deficits, except for GH. Fasting serum irisin was measured with an enzyme immunoassay, and HOMA-IR, QUICKI and HOMA-β were calculated.
  
  
  RESULTS
  Fasting irisin levels (ng/ml) were similar in normal [208.42 (168.44-249.23)] and HP patients [195.13 (178.44-241.44)]. In the control group there were moderate significant positive correlations between irisin and BMI, waist circumference, leptin, fasting insulin, HOMA-IR, HOMA-β, triglycerides, and cholesterol. In the control group there were moderate significant negative correlations between irisin and IGF-I and QUICKI. In the hypopituitary group there were moderate significant positive correlations between irisin and body fat and HOMA-β.
  
  
  CONCLUSIONS
  We found similar irisin levels in GH deficiency hypopituitary patients when compared with normal subjects. The correlation between irisin and adiposity related factors suggests that that in the case of this clinical model, irisin is regulated by adiposity and not by GH.
authors.affiliation: Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain.|Instituto de Investigación Biomédica (INIBIC), University Hospital A Coruña, A Coruña, Spain.
authors.forename: Lara
authors.initials: L
authors.lastname: Pena-Bello
authors.affiliation: Clinical Epidemiology and Biostatistics Unit, University Hospital A Coruña, A Coruña, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Pértega-Diaz
authors.affiliation: Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain.|Instituto de Investigación Biomédica (INIBIC), University Hospital A Coruña, A Coruña, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Sangiao-Alvarellos
authors.affiliation: Department of Endocrinology, University Hospital A Coruña, A Coruña, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Outeiriño-Blanco
authors.affiliation: Department of Endocrinology, University Hospital A Coruña, A Coruña, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Eiras-Leal
authors.affiliation: Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain.|Instituto de Investigación Biomédica (INIBIC), University Hospital A Coruña, A Coruña, Spain.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Varela-Rodriguez
authors.affiliation: Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain.|Instituto de Investigación Biomédica (INIBIC), University Hospital A Coruña, A Coruña, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Juiz-Valiña
authors.affiliation: Instituto de Investigación Biomédica (INIBIC), University Hospital A Coruña, A Coruña, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Pérez-Fontán
authors.affiliation: Instituto de Investigación Biomédica (INIBIC), University Hospital A Coruña, A Coruña, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Cordido
authors.affiliation: Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain.|Instituto de Investigación Biomédica (INIBIC), University Hospital A Coruña, A Coruña, Spain.|Department of Endocrinology, University Hospital A Coruña, A Coruña, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Cordido
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005353:Fibronectins / Q000097:blood*; D006801:Humans; D007018:Hypopituitarism / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism
chemical_list: C577593:FNDC5 protein, human; D005353:Fibronectins