title: Biochemical assessment of disease control in acromegaly: reappraisal of the glucose suppression test in somatostatin analogue (SA) treated patients.
abstract: BACKGROUND
  It is recommended not to measure growth hormone during oral glucose suppression (oral glucose tolerance test) during somatostatin analog treatment in acromegaly. However, we have observed that failure to suppress growth hormone in response to oral glucose tolerance test during somatostatin analog unmasks insufficient disease control and hypothesize that somatostatin analog also induces insufficient growth hormone suppression to mixed meals.
  
  
  METHODS
  We therefore compared serum growth hormone levels during two mixed meals in patients with controlled insulin-like growth factor-I levels after either surgery alone (n = 9) or somatostatin analog treatment (n = 9). The patients were unbiasedly matched for gender and insulin-like growth factor-I and studied twice in the following order: (1) during a 6 h growth hormone day curve including two mixed meals and (2) during a 3 h growth hormone profile including 60 min fasting followed by a 2-h oral glucose tolerance test.
  
  
  RESULTS
  During the day curve growth hormone levels were elevated in the somatostatin analog group (P = 0.008) and growth hormone levels 1 h after each meal declined significantly only in the surgery group (P = 0.02). During the oral glucose tolerance test the two groups had similar growth hormone levels prior to the glucose load (P = 0.6), whereas a significant 66% suppression was observed after glucose only in the surgery group (P = 0.001).
  
  
  CONCLUSIONS
  (1) Patients controlled by somatostatin analog fail to suppress growth hormone in response to both mixed meals and oral glucose tolerance test (2) This phenomenon is likely to result in elevated serum growth hormone levels during everyday life in somatostatin analog-treated patients, (3) We postulate that measuring growth hormone levels during oral glucose tolerance test is useful to unmask potential somatostatin analog under-treatment in the presence of 'safe' insulin-like growth factor-I levels.
authors.affiliation: The Medical Research Laboratories, Department of Endocrinology and Internal Medicine, Clinical Institute, Aarhus University Hospital, Nørrebrogade 44, Aarhus C, 8000, Denmark. maiarl@rm.dk.
authors.forename: Mai
authors.initials: M
authors.lastname: Christiansen Arlien-Søborg
authors.affiliation: The Medical Research Laboratories, Department of Endocrinology and Internal Medicine, Clinical Institute, Aarhus University Hospital, Nørrebrogade 44, Aarhus C, 8000, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Trolle
authors.affiliation: The Medical Research Laboratories, Department of Endocrinology and Internal Medicine, Clinical Institute, Aarhus University Hospital, Nørrebrogade 44, Aarhus C, 8000, Denmark.
authors.forename: Elin
authors.initials: E
authors.lastname: Alvarson
authors.affiliation: The Medical Research Laboratories, Department of Endocrinology and Internal Medicine, Clinical Institute, Aarhus University Hospital, Nørrebrogade 44, Aarhus C, 8000, Denmark.
authors.forename: Amanda
authors.initials: A
authors.lastname: Bæk
authors.affiliation: The Medical Research Laboratories, Department of Endocrinology and Internal Medicine, Clinical Institute, Aarhus University Hospital, Nørrebrogade 44, Aarhus C, 8000, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Dal
authors.affiliation: The Medical Research Laboratories, Department of Endocrinology and Internal Medicine, Clinical Institute, Aarhus University Hospital, Nørrebrogade 44, Aarhus C, 8000, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Otto Lunde Jørgensen
mesh_terms: D000172:Acromegaly / Q000097:blood* / Q000188:drug therapy / Q000601:surgery; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005951:Glucose Tolerance Test; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D013004:Somatostatin / Q000031:analogs & derivatives*
chemical_list: D001786:Blood Glucose; D019382:Human Growth Hormone; D013004:Somatostatin; D007334:Insulin-Like Growth Factor I
keywords: Acromegaly; GH; IGF-I; Oral glucose suppression test; Somatostatin analog