title: Microvascular autoregulation in children and adolescents with type 1 diabetes mellitus.
abstract: OBJECTIVE
  Deterioration of microvascular function may have an early onset in individuals with type 1 diabetes mellitus. We hypothesised that microvascular autoregulation is impaired in children with type 1 diabetes and can be detected non-invasively by postocclusive reactive hyperaemia (PORH).
  
  
  METHODS
  Microvascular autoregulation was assessed in 58 children with type 1 diabetes and 58 age- and sex-matched healthy controls by PORH using laser Doppler fluxmetry. Baseline perfusion, biological zero (defined as a 'no flow' laser Doppler signal during suprasystolic occlusion), peak perfusion following occlusion, time to peak and recovery time (time until baseline perfusion is resumed) were recorded and compared between the groups.
  
  
  RESULTS
  Peak perfusion was higher in children with type 1 diabetes than in healthy controls (1.7 ± 0.93 AU [arbitrary units] vs 1.29 ± 0.46 AU; p = 0.004), and biological zero was lower in children with type 1 diabetes vs controls (0.14 ± 0.04 AU vs 0.19 ± 0.04 AU; p < 0.0001). No differences were seen between the groups in baseline perfusion, time to peak during PORH and recovery time following PORH.
  
  
  CONCLUSIONS
  PORH reveals impaired microvascular autoregulation in children with type 1 diabetes. The higher peak perfusion might reflect a decline in the vasoconstrictive ability of arteriolar smooth muscle cells upstream of capillary beds in children with type 1 diabetes.
authors.affiliation: Department of Medicine II, Division of Angiology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: O
authors.initials: O
authors.lastname: Schlager
authors.forename: A
authors.initials: A
authors.lastname: Hammer
authors.forename: A
authors.initials: A
authors.lastname: Willfort-Ehringer
authors.forename: M
authors.initials: M
authors.lastname: Fritsch
authors.forename: B
authors.initials: B
authors.lastname: Rami-Merhar
authors.forename: E
authors.initials: E
authors.lastname: Schober
authors.forename: K
authors.initials: K
authors.lastname: Nagl
authors.forename: A
authors.initials: A
authors.lastname: Giurgea
authors.forename: C
authors.initials: C
authors.lastname: Margeta
authors.forename: S
authors.initials: S
authors.lastname: Zehetmayer
authors.forename: G H
authors.initials: GH
authors.lastname: Schernthaner
authors.forename: R
authors.initials: R
authors.lastname: Koppensteiner
authors.forename: M E
authors.initials: ME
authors.lastname: Gschwandtner
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000502:physiology*