title: A randomized controlled trial of exercise training on cardiovascular and autonomic function among renal transplant recipients.
abstract: BACKGROUND
  There are conflicting data regarding the effects of renal transplantation (RT) on uraemic autonomic dysfunction. Moreover, no study has examined the impact of physical training on the cardiac autonomic function in RT patients. Thus, we studied the effects of exercise training on heart rate variability (HRV) and arterial baroreflex sensitivity (BRS), which are sensitive markers of cardiac autonomic outflow, in RT recipients.
  
  
  METHODS
  Eleven patients (Exercise group-aged 52.1 ± 5.6 years) were studied before and after 6 months of exercise training. Twelve age- and sex- matched RT patients (Sedentary) and 12 healthy sedentary individuals (Healthy), who remained untrained, served as controls. At baseline and follow-up, all the subjects underwent cardiopulmonary exercise testing for the evaluation of peak oxygen consumption (VO2peak), a tilt test for the evaluation of BRS and baroreflex effectiveness index (BEI) and an ambulatory 24-h Holter monitoring for time- and frequency-domain measures of HRV.
  
  
  RESULTS
  In the exercise group, VO2peak increased by 15.8% (P < 0.05) and all depressed HRV and BRS indices were significantly improved after training. Specifically, the standard deviation of all normal-to-normal (NN) intervals (SDNN) significantly increased by 92.5%, the root-mean-square of the differences between consecutive NN intervals by 45.4%, the percentage value of NN50 count by 58.2%, the high-frequency by 74.8% and low-frequency spectral power by 41.6%, BRS by 43.7% and BEI by 57.3%. None of the variables studied was altered over time in either control group.
  
  
  CONCLUSIONS
  The increased cardiorespiratory fitness by exercise training was associated with an improved BRS function and a modification of the sympathovagal control of HRV towards a persistent increase in parasympathetic tone. These alterations may lead to a better cardiovascular prognosis in RT recipients.
authors.affiliation: Laboratory of Sports Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece. ekouidi@med.auth.gr
authors.forename: Evangelia
authors.initials: E
authors.lastname: Kouidi
authors.forename: George
authors.initials: G
authors.lastname: Vergoulas
authors.forename: Maria
authors.initials: M
authors.lastname: Anifanti
authors.forename: Asterios
authors.initials: A
authors.lastname: Deligiannis
mesh_terms: D000293:Adolescent; D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000209:etiology / Q000517:prevention & control*; D017704:Baroreflex / Q000502:physiology; D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control*; D016022:Case-Control Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005081:Exercise Therapy; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011379:Prognosis; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000628:therapy; D055815:Young Adult
keywords: baroreflex sensitivity; cardiac autonomic function; exercise training; heart-rate variability; renal transplantation