title: Oxidative stress is associated with decreased heart rate variability in patients with chronic kidney disease.
abstract: OBJECTIVE
  Elevated oxidative stress and reduced heart rate variability (HRV) is prevalent in patients with chronic kidney disease (CKD) and is associated with increased morbidity and mortality. Previous studies have identified a positive association between elevated oxidative stress and autonomic dysfunction, however this relationship has not yet been investigated in the CKD population.
  
  
  METHODS
  Plasma was collected from 78 patients with stage 3-4 CKD (estimated glomerular filtration rate 25-60 ml/min/1.73 m2) for the assessment of oxidative stress, including plasma total F2-isoprostanes, glutathione peroxidase activity and total antioxidant capacity. Time and frequency HRV parameters were measured from a three lead electrocardiogram.
  
  
  RESULTS
  Participants with elevated F2-isoprostanes had reduced HRV compared to patients with normal levels of F2-isoprostanes. A number of HRV parameters were found to be inversely correlated with F2-isoprostanes in all CKD patients, including SDNN (r = -0.337; P < 0.01), VLF (r = -0.281, P = 0.01), LF (r = -0.315, P < 0.01) and total power (r = -0.288, P = 0.01). Multiple linear regression found F2-isoprostanes to be an independent predictor of SDNN (r2= 0.287, β = -0.272, P = 0.01).
  
  
  CONCLUSIONS
  Oxidative stress is significantly and independently associated with HRV in patients with CKD. Identifying oxidative stress in the pathogenesis of autonomic dysfunction may help target therapeutic strategies.
authors.affiliation: a School of Human Movement and Nutrition Sciences, The University of Queensland , Brisbane , Australia.
authors.forename: Shannon B
authors.initials: SB
authors.lastname: Fadaee
authors.affiliation: a School of Human Movement and Nutrition Sciences, The University of Queensland , Brisbane , Australia.
authors.forename: Kassia S
authors.initials: KS
authors.lastname: Beetham
authors.affiliation: b Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Centre , Dallas , USA.
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Howden
authors.affiliation: c School of Medicine, The University of Queensland , Brisbane , Australia.|d Cardiovascular Imaging Research Group, The University of Queensland , Brisbane , Australia.
authors.forename: Tony
authors.initials: T
authors.lastname: Stanton
authors.affiliation: c School of Medicine, The University of Queensland , Brisbane , Australia.|e Department of Nephrology , Princess Alexandra Hospital , Brisbane , Australia.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Isbel
authors.affiliation: a School of Human Movement and Nutrition Sciences, The University of Queensland , Brisbane , Australia.
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Coombes
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000032:analysis; D003430:Cross-Sectional Studies; D028441:F2-Isoprostanes / Q000097:blood; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D012044:Regression Analysis; D051436:Renal Insufficiency, Chronic / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D000975:Antioxidants; D028441:F2-Isoprostanes; D005979:Glutathione Peroxidase
keywords: Autonomic dysfunction; Chronic kidney disease; Heart rate variability; Oxidative stress