title: Sex-dependent association between heart rate variability and pulse pressure in haemodialysis patients.
abstract: OBJECTIVE
  Increased pulse pressure (PP) is associated with increased cardiovascular mortality in haemodialysis (HD) patients. Autonomic imbalance is common in HD patients and predisposes to sudden cardiac death, but its relationship to PP is unknown. We investigated the relationship between cardiac autonomic modulation assessed by heart rate variability (HRV) and PP in HD patients.
  
  
  METHODS
  Continuous electrocardiograms recorded during HD sessions were repeated 5 times at 2-week intervals in stable HD patients. The high-frequency (HF) and low-frequency (LF) components and the LF/HF ratio of HRV were calculated during the first and last hour of the recordings. These values and the corresponding systolic blood pressure (SBP), diastolic blood pressure (DBP) and PP measurements were averaged in repeated recordings of each patient.
  
  
  RESULTS
  Seventy-six patients were included in the final analysis (aged 61 ± 15 years, 32% females, 37% diabetics). In male patients, LF/HF correlated inversely with pre- and post-HD PP (r = -0.369, p = 0.007 and r = -0.546, p = 0.000, respectively), positively with pre- and post-HD DBP (r = 0.358, p = 0.009 and r = 0.306, p = 0.028, respectively) and inversely with post-HD SBP (r = -0.350, p = 0.011). In female patients, LF/HF correlated positively with post-HD SBP (r = 0.422, p = 0.040).
  
  
  CONCLUSIONS
  We observed an association between PP and HRV in male HD patients. Sex differences may be important for cardiac risk assessment.
authors.affiliation: Cardiovascular Sciences Research Centre, St. George's University of London, UK.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Poulikakos
authors.forename: Marek
authors.initials: M
authors.lastname: Malik
authors.forename: Debasish
authors.initials: D
authors.lastname: Banerjee
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D048909:Diabetes Complications / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012737:Sex Factors