title: Hypoglycemia counterregulation during sleep.
abstract: OBJECTIVE
  In insulin-treated patients with diabetes, episodes of severe hypoglycemia often occur during sleep, which might reflect an altered counterregulation and reduced awareness. This study examined the influence of sleep on the counterregulatory response to hypoglycemia in healthy subjects.
  
  
  METHODS
  Subjects participated in two experimental conditions; statistical tests relied on within subject comparisons.
  
  
  METHODS
  University hospital sleep laboratory.
  
  
  METHODS
  15 healthy young men.
  
  
  METHODS
  Hypoglycemia (2.8 mmol/l) was induced for 45 min by insulin infusion once during sleep and once at the same time of night while being awake.
  
  
  RESULTS
  Counterregulatory hormone concentrations (epinephrine, norepinephrine, ACTH and cortisol) and sleep recordings were obtained. Differences in the hormonal responses to hypoglycemia between sleep and wake conditions remained non-significant, indicating that sleep does not exert a primary influence on the strength of counterregulation. However, the glycemic threshold for the onset of counterregulation was significantly changed during sleep: The average onset threshold for epinephrine and norepinephrine counterregulation was 3.3 +/- 0.1 mmol/l for the wake condition and 2.7 +/- 0.1 mmol/l for the sleep condition (P < 0.001). A decrease in sleep depth coincided with the onset of the counterregulatory response, with most subjects showing signs of awakening.
  
  
  CONCLUSIONS
  During sleep, the organism is less sensitive to hypoglycemia. Hypoglycemia per se has an awakening effect.
authors.affiliation: Departments of Neuroendocrinology, Medical University of Lübeck, 23538 Lübeck, Germany. gais@kfg.mu-luebeck.de
authors.forename: Steffen
authors.initials: S
authors.lastname: Gais
authors.forename: Jan
authors.initials: J
authors.lastname: Born
authors.forename: Achim
authors.initials: A
authors.lastname: Peters
authors.forename: Bernd
authors.initials: B
authors.lastname: Schultes
authors.forename: Britta
authors.initials: B
authors.lastname: Heindl
authors.forename: Horst L
authors.initials: HL
authors.lastname: Fehm
authors.forename: Kern
authors.initials: K
authors.lastname: Werner
mesh_terms: D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D004837:Epinephrine / Q000097:blood / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D007003:Hypoglycemia / Q000139:chemically induced / Q000378:metabolism*; D007328:Insulin / Q000009:adverse effects; D008297:Male; D009638:Norepinephrine / Q000097:blood / Q000378:metabolism*; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology
chemical_list: D001786:Blood Glucose; D007328:Insulin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine