title: Distinct metabolic surrogates predict basal and rebound GH secretion after glucose ingestion in men.
abstract: BACKGROUND
  GH secretion declines rapidly after glucose ingestion and then recovers to higher-than-baseline levels (rebound GH release).
  
  
  OBJECTIVE
  Selective metabolic markers predict the magnitude of glucose-suppressed GH release and postglucose rebound-like GH secretion.
  
  
  METHODS
  Prospectively randomized crossover study of GH secretion after glucose vs. water ingestion.
  
  
  METHODS
  The study was conducted at a clinical translational research center.
  
  
  METHODS
  Sixty-nine healthy men aged 19-78 yr with a body mass index of 18-39 kg/m(2) participated in the study.
  
  
  RESULTS
  OUTCOMES included nadir vs. peak GH concentrations and basal vs. pulsatile GH secretion.
  
  
  RESULTS
  Mean nadir GH concentrations were determined positively by sex hormone binding globulin (SHBG) after glucose administration (R(2) = 0.088, P = 0.0077). Peak rebound GH concentrations were related positively to adiponectin and negatively to computed tomography-estimated abdominal visceral fat (AVF) (R(2) = 0.182, P = 0.00049) after glucose ingestion. Deconvolution analysis showed that SHBG specifically predicted basal (nonpulsatile) GH secretion after glucose exposure (R(2) = 0.153, P = 0.00052). In contrast, together exercise history and adiponectin (both positively) and AVF (negatively) predicted pulsatile GH escape after glucose suppression (R(2) = 0.206, P = 0.00043). Moreover, adiponectin uniquely determined the size (mass), and AVF the mode (duration), of GH secretory bursts after glucose exposure (both P < 0.006).
  
  
  CONCLUSIONS
  Glucose ingestion provides a clinical model for investigating complementary metabolic surrogates that determine suppression and recovery of basal and pulsatile GH secretion in healthy men.
authors.affiliation: Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Iranmanesh
authors.forename: Donna
authors.initials: D
authors.lastname: Lawson
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Veldhuis
mesh_terms: D052242:Adiponectin / Q000097:blood; D000328:Adult; D000368:Aged; D001823:Body Composition / Q000502:physiology; D018592:Cross-Over Studies; D005215:Fasting / Q000502:physiology; D005947:Glucose / Q000008:administration & dosage*; D019382:Human Growth Hormone / Q000097:blood* / Q000378:metabolism*; D006801:Humans; D050152:Intra-Abdominal Fat / Q000378:metabolism; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D014867:Water / Q000008:administration & dosage; D055815:Young Adult
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin; D020738:Leptin; D012738:Sex Hormone-Binding Globulin; D014867:Water; D019382:Human Growth Hormone; D005947:Glucose