title: A comparison of flow-mediated dilatation and peripheral artery tonometry for measurement of endothelial function in healthy individuals and patients with peripheral arterial disease.
abstract: OBJECTIVE
  Flow-mediated dilatation (FMD) and peripheral artery tonometry (PAT) are commonly used methods for assessing endothelial function in a research setting but it is unclear how well they correlate. This study aimed to compare and correlate these methods in patients with peripheral arterial disease (PAD) and in healthy individuals.
  
  
  METHODS
  FMD and PAT measurements were obtained as samples of convenience from 26 patients with PAD and 25 healthy subjects. FMD was defined as the percentage increase in the brachial artery diameter after distal occlusion and PAT was measured using the reactive hyperaemia index (RHI).
  
  
  RESULTS
  Patients with PAD had a significantly lower FMD than healthy subjects (2.43% vs. 5.80%, p < 0.001). No difference was found in RHI between the two groups. No correlation was found between the FMD and RHI in subjects with PAD (r = 0.284, p = 0.160), in healthy subjects (r = 0.153, p = 0.464) or when both groups were combined (r = 0.174, p = 0.22).
  
  
  CONCLUSIONS
  The lack of change in RHI in PAD patients suggests that PAT is not a sensitive measure of endothelial function. The lack of correlation suggests that FMD and PAT are not interchangeable. PAT should not be used as a substitute for FMD as a measure of endothelial function.
authors: Department of Vascular Surgery, Flinders Medical Centre and Flinders University, Bedford Park, South Australia, Australia.
authors: R B
authors: RB
authors: Allan
authors: C L
authors: CL
authors: Delaney
authors: M D
authors: MD
authors: Miller
authors: J I
authors: JI
authors: Spark
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004106:Dilatation / Q000379:methods*; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods*; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000175:diagnosis / Q000503:physiopathology*; D016491:Peripheral Vascular Diseases / Q000175:diagnosis / Q000503:physiopathology*; D014463:Ultrasonography; D055815:Young Adult