title: Impaired glucose metabolism in Japanese patients with acromegaly is restored after successful pituitary surgery if pancreatic {beta}-cell function is preserved.
abstract: OBJECTIVE
  Impaired glucose metabolism is common in acromegaly, but it is not clear how glucose metabolism is impaired or what predicts its restoration after cure of the disease. To identify factors involved in the impairment of glucose metabolism in acromegaly, we evaluated clinical parameters before and immediately after surgical cure of the disease.
  
  
  METHODS
  We retrospectively analyzed clinical data of 92 consecutive Japanese patients with acromegaly who underwent successful pituitary surgery. Patients who had received medical therapy for acromegaly or insulin treatment for diabetes were excluded. We evaluated insulin resistance (IR) and pancreatic β-cell function in addition to GH and IGF1 levels before and after surgery. Results In this study of Japanese patients with acromegaly, average body mass index (BMI) was 23.4, and no patient had a BMI>30. IR was involved in the impairment of glucose metabolism, which was restored upon surgical cure of acromegaly if β-cell function was preserved. Insufficient β-cell function did not improve after normalization of GH/IGF1 and was associated with impaired glucose metabolism before and after surgery.
  
  
  RESULTS
  of receiver operating characteristic analysis of preoperative clinical parameters suggest that insulinogenic index (IGI) >0.50 best predicts restoration of normal glucose metabolism upon cure of acromegaly in Japanese patients.
  
  
  CONCLUSIONS
  IR impairs glucose metabolism in acromegaly. Once β-cell function is impaired, abnormal glucose metabolism persists even after cure of acromegaly. IGI>0.50 indicates that β-cell function is preserved in non-obese Japanese patients with acromegaly.
authors.affiliation: Division of Endocrinology Pituitary Surgery, Toranomon Hospital Endocrine Center, 2-2-2 Toranomon Minato-ku, Tokyo 105-8470, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kinoshita
authors.forename: Hiroko
authors.initials: H
authors.lastname: Fujii
authors.forename: Akira
authors.initials: A
authors.lastname: Takeshita
authors.forename: Manabu
authors.initials: M
authors.lastname: Taguchi
authors.forename: Megumi
authors.initials: M
authors.lastname: Miyakawa
authors.forename: Kenich
authors.initials: K
authors.lastname: Oyama
authors.forename: Shozo
authors.initials: S
authors.lastname: Yamada
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takeuchi
mesh_terms: D000172:Acromegaly / Q000378:metabolism* / Q000601:surgery*; D000328:Adult; D044466:Asian People; D005260:Female; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006801:Humans; D050417:Insulin-Secreting Cells / Q000166:cytology* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000601:surgery*; D012189:Retrospective Studies
chemical_list: D005947:Glucose