title: Evaluation of endothelial function using finger plethysmography.
abstract: BACKGROUND
  The aims of this study were to establish the optimum duration of blood flow occlusion to obtain maximal response and to compare the response after lower-arm and upper-arm occlusion.
  
  
  METHODS
  Pulse wave amplitude was analysed using a novel finger plethysmograph (EndoPat; Itamar). For measuring reactive hyperaemic index (RHI) induced by forearm cuff occlusion, 30 healthy subjects were examined at different days in a random order of four cuff occlusion times (1.5, 3, 5 and 8 min). RHI induced by 5 min upper-arm cuff occlusion was also measured in 20 subjects.
  
  
  RESULTS
  Average RHI was lower with 1.5 and 3 min forearm occlusion compared with 8 min forearm occlusion (P = 0.002 and P = 0.024). There was no significant difference between values of 5 min and 8 min forearm occlusion and between 5 min forearm and 5 min upper-arm occlusion (P = 0.1). All subjects reported less discomfort after forearm occlusion compared with upper-arm occlusion.
  
  
  CONCLUSIONS
  Maximum response was reached after 5 min of blood flow occlusion and therefore this occlusion time is recommended. The response after forearm and upper-arm occlusion did not differ significantly. Forearm occlusion might be preferred as this caused less discomfort.
authors: Department of Medicine, Aker University Hospital and Oslo University, Oslo 0514, Norway.
authors: A K
authors: AK
authors: Faizi
authors: D W
authors: DW
authors: Kornmo
authors: S
authors: S
authors: Agewall
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000098:blood supply* / Q000502:physiology*; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D010991:Plethysmography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity