title: Heart rate variability in advanced chronic kidney disease with or without diabetes: midterm effects of the initiation of chronic haemodialysis therapy.
abstract: BACKGROUND
  Previous studies in different clinical settings have established heart rate variability (HRV) as a significant independent risk factor for higher mortality and cardiac death. The aim of this study was to examine the effect of chronic haemodialysis therapy on time- and frequency-domain parameters of HRV in diabetic and non-diabetic patients with chronic kidney disease (CKD).
  
  
  METHODS
  We studied 25 patients with stage 4 CKD and type 2 diabetes mellitus (CKD4+DM), 25 patients with stage 4 CKD without diabetes (CKD4), 25 patients with type 2 diabetes mellitus (DM) and 25 healthy subjects (HS). The study was performed in two phases. In the first phase, a 24-h Holter electrocardiographic (ECG) monitoring was performed in all subjects. The patients with stage 4 CKD were followed up until they progressed to stage 5, and in the second phase of the study, they underwent a 24-h Holter ECG monitoring after completion of 3 months of conventional haemodialysis treatment.
  
  
  RESULTS
  In the first phase of the study, a reduction in cardiac sympathetic activity in CKD4 patients (significantly lower SDNN, SDANN/5 min, SD and VLF vs. HS) and worse autonomic function in CKD4+DM patients (significantly lower SDNN, SDANN/5 min, SD, VLF and LF/HF) vs. HS, DM and CKD4 was observed. After 3 months of dialysis therapy, the patients with CKD+DM showed a significant improvement only in the time-domain parameter SDANN/5 min, while the time-domain parameters SDNN, SDANN/5 min and SD were improved in CKD patients without diabetes. Frequency-domain parameters of HRV remained unchanged in both groups.
  
  
  CONCLUSIONS
  CKD is associated with worse cardiac autonomic function. Haemodialysis therapy for 3 months improves some indices of HRV, and this effect is more pronounced in non-diabetic subjects. Our findings suggest that the improvement of HRV after the initiation of chronic dialysis therapy can ameliorate clinical outcomes and survival in patients with end-stage renal disease.
authors.affiliation: Renal Dialysis Unit, Pantokrator Clinic, Athens, Greece. milmagr@yahoo.gr
authors.forename: Maria
authors.initials: M
authors.lastname: Mylonopoulou
authors.forename: Nicholas
authors.initials: N
authors.lastname: Tentolouris
authors.forename: Stavros
authors.initials: S
authors.lastname: Antonopoulos
authors.forename: Sotirios
authors.initials: S
authors.lastname: Mikros
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Katsaros
authors.forename: Andreas
authors.initials: A
authors.lastname: Melidonis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Sevastos
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Katsilambros
mesh_terms: D000328:Adult; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis