title: Effects of dialysate glucose concentration on heart rate variability in chronic hemodialysis patients: results of a prospective randomized trial.
abstract: BACKGROUND
  Chronic hemodialysis (HD) patients suffer from an appallingly high cardiovascular mortality. During HD, patients are exposed to dialysate glucose, which may alter blood glucose levels and thus exert effects on the autonomic nervous system. Heart rate variability (HRV) is an established indicator of autonomic nervous system activity and a predictor of cardiovascular outcomes. This study investigated the effects of two commonly used dialysate glucose concentrations [100 mg/dl (HD100), and 200 mg/dl (HD200)] on HRV in chronic HD patients.
  
  
  METHODS
  In this prospective, randomized, controlled, single-masked, cross-over trial, subjects were randomized to receive HD100 or HD200 for a period of 3 weeks followed by a cross-over to the respective other dialysate (www.clinicaltrials.gov #NCT00618033). Blood glucose and insulin levels were measured before and after HD. Intradialytic Holter electrocardiograms were recorded and HRV time domain, frequency domain and complexity parameters analyzed.
  
  
  RESULTS
  Twenty-three HD patients (age 56 ± 12 years, 11 male, 14 black, 11 with diabetes) were studied. Diabetic subjects showed significantly higher serum glucose levels with HD200 as compared to HD100 (HD100: 146 ± 48 mg/dl; HD200: 192 ± 57 mg/dl; p < 0.01); this hyperglycemia was accompanied by an increase of the high-frequency band of HRV (p = 0.019), a reflection of increased parasympathetic activity. HRV did not change in nondiabetic subjects.
  
  
  CONCLUSIONS
  In diabetic subjects, the use of HD200 increased vagal tone. Given the importance of sympathetic activation to counteract intradialytic hypotension, our findings support the use of HD100 in diabetic HD patients.
authors: Department of Bioengineering, Politecnico di Milano, Italy.
authors: Manuela
authors: M
authors: Ferrario
authors: Jochen G
authors: JG
authors: Raimann
authors: Stephan
authors: S
authors: Thijssen
authors: Maria Gabriella
authors: MG
authors: Signorini
authors: Anja
authors: A
authors: Kruse
authors: Jose A
authors: JA
authors: Diaz-Buxo
authors: Sergio
authors: S
authors: Cerutti
authors: Nathan W
authors: NW
authors: Levin
authors: Peter
authors: P
authors: Kotanko