title: Circulating acylghrelin levels are suppressed by insulin and increase in response to hypoglycemia in healthy adult volunteers.
abstract: OBJECTIVE
  Ghrelin has glucoregulatory and orexigenic actions, but its role in acute hypoglycemia remains uncertain. We aimed to investigate circulating levels of acylghrelin (AG) and unacylated ghrelin (UAG) in response to hyperinsulinemia and to hypoglycemia.
  
  
  METHODS
  A randomized, single-blind, placebo-controlled crossover study including 3 study days was performed at a university hospital clinical research center.
  
  
  METHODS
  Nine healthy men completed 3 study days: i) saline control (CTR), ii) hyperinsulinemic euglycemia (HE) (bolus insulin 0.1 IE/kg i.v. and glucose 20% i.v. for 105 min, plasma glucose ≈5 mmol/l), and iii) hyperinsulinemic hypoglycemia (HH) (bolus insulin 0.1 IE/kg i.v.).
  
  
  RESULTS
  HH and HE suppressed AG concentrations at t=45-60 min as compared with CTR (P<0.05). At t=90 min, a rebound increase in AG was observed in response to HH as compared with both HE and CTR (P<0.05). UAG also decreased during HH and HE at t=45 min (P<0.05), whereas the AG-to-UAG ratio remained unaffected.
  
  
  CONCLUSIONS
  This study demonstrates that AG and UAG are directly suppressed by hyperinsulinemia and that AG concentrations increase after a latency of ≈1 h in response to hypoglycemia, suggesting a potential counterregulatory role of AG.
authors.affiliation: Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark esben.lauritzen@clin.au.dk.
authors.forename: Esben S
authors.initials: ES
authors.lastname: Lauritzen
authors.affiliation: Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Voss
authors.affiliation: Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark.
authors.forename: Ulla
authors.initials: U
authors.lastname: Kampmann
authors.affiliation: Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark.
authors.forename: Annette
authors.initials: A
authors.lastname: Mengel
authors.affiliation: Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark.
authors.forename: Mikkel H
authors.initials: MH
authors.lastname: Vendelbo
authors.affiliation: Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark.
authors.forename: Jens O L
authors.initials: JO
authors.lastname: Jørgensen
authors.affiliation: Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Møller
authors.affiliation: Medical Research LaboratoryAarhus University, Nørrebrogade 44, Building 3B, 8000 Aarhus C, DenmarkDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, Building 2A, 8000 Aarhus C, Denmark.
authors.forename: Esben T
authors.initials: ET
authors.lastname: Vestergaard
mesh_terms: D000215:Acylation; D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D005230:Fatty Acids, Nonesterified / Q000097:blood; D054439:Ghrelin / Q000097:blood*; D064368:Healthy Volunteers; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D007003:Hypoglycemia / Q000097:blood* / Q000139:chemically induced; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D008297:Male; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D054439:Ghrelin; D007328:Insulin; D019382:Human Growth Hormone