title: IGF-I levels reflect hypopituitarism severity in adults with pituitary dysfunction.
abstract: OBJECTIVE
  To evaluate the utility of Insulin-like growth factor I (IGF-I) standard deviation score (SDS) as a surrogate marker of severity of hypopituitarism in adults with pituitary pathology.
  
  
  METHODS
  We performed a retrospective data analysis, including 269 consecutive patients with pituitary disease attending a tertiary endocrine clinic in 1990-2015. The medical files were reviewed for the complete pituitary hormone profile, including IGF-I, and clinical data. Age-adjusted assay reference ranges of IGF-I were used to calculate IGF-I SDS for each patient. The main outcome measures were positive and negative predictive values of low and high IGF-I SDS, respectively, for the various pituitary hormone deficiencies.
  
  
  RESULTS
  IGF-I SDS correlated negatively with the number of altered pituitary axes (p < 0.001). Gonadotropin was affected in 76.6 % of cases, followed by thyrotropin (58.4 %), corticotropin (49.1 %), and prolactin (22.7 %). Positive and negative predictive values yielded a clear trend for the probability of low/high IGF-I SDS for all affected pituitary axes. Rates of diabetes insipidus correlated with IGF-I SDS values both for the full study population, and specifically for patients with non-functioning pituitary adenomas.
  
  
  CONCLUSIONS
  IGF-I SDS can be used to evaluate the somatotroph function, as a valid substitute to absolute IGF-I levels. Moreover, IGF-I SDS predicted the extent of hypopituitarism in adults with pituitary disease, and thus can serve as a marker of hypopituitarism severity.
authors.affiliation: Endocrine Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Amit
authors.initials: A
authors.lastname: Tirosh
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.|Endocrinology Clinic, Division of Maternal Fetal Medicine, Helen Schneider Hospital for Women, Rabin Medical Center, Petach Tikva, Israel.
authors.forename: Yoel
authors.initials: Y
authors.lastname: Toledano
authors.affiliation: Endocrine Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Hiba
authors.initials: H
authors.lastname: Masri-Iraqi
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.|Tel Aviv-Jaffa District Clalit Health Services, Tel Aviv, Israel.
authors.forename: Yoav
authors.initials: Y
authors.lastname: Eizenberg
authors.affiliation: Endocrine Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Gloria
authors.initials: G
authors.lastname: Tzvetov
authors.affiliation: Endocrine Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Dania
authors.initials: D
authors.lastname: Hirsch
authors.affiliation: Endocrine Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Carlos
authors.initials: C
authors.lastname: Benbassat
authors.affiliation: Endocrine Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Eyal
authors.initials: E
authors.lastname: Robenshtok
authors.affiliation: Endocrine Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel. ilanshi@clalit.org.il.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. ilanshi@clalit.org.il.
authors.forename: Ilan
authors.initials: I
authors.lastname: Shimon
mesh_terms: D000236:Adenoma / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D000324:Adrenocorticotropic Hormone / Q000172:deficiency / Q000378:metabolism; D000328:Adult; D000368:Aged; D016371:Cranial Irradiation; D005260:Female; D005640:Follicle Stimulating Hormone / Q000172:deficiency / Q000378:metabolism; D006065:Gonadotropins, Pituitary / Q000172:deficiency / Q000378:metabolism; D006801:Humans; D007018:Hypopituitarism / Q000209:etiology / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000172:deficiency / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010900:Pituitary Diseases / Q000150:complications / Q000378:metabolism; D010902:Pituitary Gland / Q000601:surgery; D010911:Pituitary Neoplasms / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D011388:Prolactin / Q000172:deficiency / Q000378:metabolism; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013739:Testosterone / Q000378:metabolism; D013972:Thyrotropin / Q000172:deficiency / Q000378:metabolism; D013974:Thyroxine / Q000378:metabolism
chemical_list: D006065:Gonadotropins, Pituitary; D013739:Testosterone; D007334:Insulin-Like Growth Factor I; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D013974:Thyroxine
keywords: Adult; Hypopituitarism; IGF-I; Pituitary