title: Long-term changes in serum IGF-1 levels after successful surgical treatment of growth hormone-secreting pituitary adenoma.
abstract: BACKGROUND
  Successful treatment of acromegaly is known to normalize serum insulin-like growth factor 1 (IGF-1) levels within days after surgery. However, our clinical observations indicate that many cases of acromegaly show delayed normalization of serum IGF-1 levels after complete tumor resection.
  
  
  OBJECTIVE
  To study long-term changes of the serum IGF-1 levels in acromegalic patients for whom surgical treatment was thought to be successful.
  
  
  METHODS
  A retrospective observational study was performed with 46 acromegalic patients with no residual tumor on sellar magnetic resonance imaging, and a nadir growth hormone of less than 0.4 μg/L on a postoperative oral glucose tolerance test.
  
  
  RESULTS
  In all patients, serum IGF-1 levels returned to the normal reference values for age and sex during the observational period (12-132 months). The mean duration from the time of surgery until IGF-1 normalization was 10 months (range, 3 days-57 months). Twenty-seven patients (59%) reached normal IGF-1 ranges within 3 months of surgery, whereas 19 patients (41%) experienced delayed (>3 months) IGF-1 normalization. Eleven patients (24%) recovered normal IGF-1 levels 12 to 57 months after surgery. The possibility of delayed IGF-1 cure was increased 8.8-fold with an immediate postoperative IGF-1 level increase of 100 μg/L.
  
  
  CONCLUSIONS
  Satisfactory remission of acromegaly by IGF-1 criteria was delayed in a large proportion of acromegalic patients, especially those with high postoperative IGF-1 levels. Hence, additional treatment can be delayed in clinically stable acromegalic patients who show no evidence of residual tumors on postoperative magnetic resonance imaging and a normal growth hormone suppressive response to a glucose load.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Asan Medical Center University of Ulsan College of Medicine, Seoul, Korea. mskim@amc.seoul.kr
authors.forename: Mi-Seon
authors.initials: MS
authors.lastname: Shin
authors.forename: Ji Hee
authors.initials: JH
authors.lastname: Yu
authors.forename: Jong Han
authors.initials: JH
authors.lastname: Choi
authors.forename: Chang Hee
authors.initials: CH
authors.lastname: Jung
authors.forename: Jenie Yoonoo
authors.initials: JY
authors.lastname: Hwang
authors.forename: Young Hyun
authors.initials: YH
authors.lastname: Cho
authors.forename: Chang Jin
authors.initials: CJ
authors.lastname: Kim
authors.forename: Min-Seon
authors.initials: MS
authors.lastname: Kim
mesh_terms: D000236:Adenoma / Q000378:metabolism* / Q000601:surgery*; D000328:Adult; D005260:Female; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000378:metabolism* / Q000601:surgery*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D007334:Insulin-Like Growth Factor I