title: Arterial stiffness assessed by digital volume pulse correlates with comorbidity in patients with ESRD.
abstract: BACKGROUND
  Digital volume pulse (DVP), a noninvasive method for indirect assessment of arterial stiffness, was not tested previously in patients with end-stage renal disease (ESRD). Therefore, we compared the DVP-derived stiffness index (SI(DVP)) with aortic pulse wave velocity (PWV) determined by means of Doppler ultrasonography in 2 groups of patients with ESRD and analyzed the correlation between SI(DVP) and comorbidity.
  
  
  METHODS
  Photoplethysmography was performed on the index finger of the dominant hand or the hand from the nonfistula arm in 49 renal transplant (TX) recipients and 48 hemodialysis (HD) patients. Pulse curves were analyzed with computer assistance. Comorbidity was assessed by using an established index.
  
  
  RESULTS
  The intrasubject variability of SI(DVP) was 5.7%. SI(DVP) and aortic PWV values correlated significantly (r = 0.66; P = 0.001) in patients with ESRD. SI(DVP) could not be assessed reliably in 25% and 6% of HD patients and TX recipients, respectively. Multivariate regression analyses showed that SI(DVP) increased with age in both HD patients and TX recipients (r = 0.61; P < 0.001) and with systolic blood pressure (r = 0.53; P < 0.025), mean arterial pressure (r = 0.47; P < 0.05), and pulse pressure (r = 0.52; P = 0.02) in TX recipients. Severity of comorbid status was associated highly with individual residuals of age-adjusted SI(DVP) in HD patients and TX recipients (P < 0.001).
  
  
  CONCLUSIONS
  DVP allows the measurement of arterial stiffness in most, but not all, patients with ESRD. SI(DVP) values correlate with comorbidity in HD patients and TX recipients.
authors.affiliation: Department of Nephrology and Hypertension, University Hospital of Bern, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sollinger
authors.forename: Markus G
authors.initials: MG
authors.lastname: Mohaupt
authors.forename: Albina
authors.initials: A
authors.lastname: Wilhelm
authors.forename: Dominik
authors.initials: D
authors.lastname: Uehlinger
authors.forename: Felix J
authors.initials: FJ
authors.lastname: Frey
authors.forename: Ute
authors.initials: U
authors.lastname: Eisenberger
mesh_terms: D000328:Adult; D001011:Aorta / Q000000981:diagnostic imaging; D001158:Arteries / Q000502:physiology*; D001794:Blood Pressure; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004548:Elasticity; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D008875:Middle Aged; D017156:Photoplethysmography; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler