EXerCise Introduction To Enhance Performance in Dialysis(EXCITE)

Background Dialysis patients show an exceedingly higher risk of death and cardiovascular complications (1). These patients are also characterized by poor physical performance and reduced quality of life. Observational findings in the United States Renal Data System (USRDS) indicated that physical rehabilitation programs after coronary artery bypass are associated with better clinical outcomes in this population (2). However, the hypothesis that physical training in dialysis patients may translate into better physical performance and clinical outcomes has never been tested in large randomized clinical trials. In studies performed so far, physical exercise was proposed during the dialysis session or between two dialysis sessions. These programs imply compliance, organization and cost problems, mainly related with intensification of visit to the dialysis centre. To limit these difficulties, a single easy-to-implement program of physical exercise for dialysis patients, prescribed in the dialysis centre but performed at home, has been recently elaborated and a pilot study has shown that this program improves physical performance in medium term (3).

Purpose This clinical trial tests whether a physical program prescribed in the dialysis centre but performed at home improves the degree of fitness and the quality of life in dialysis patients.

Study population

• Inclusion Criteria:

• 500 Patients on dialysis
• Dialysis vintage>6 months
• Age>18 years
• Signed informed consent
• Stable clinical conditions
• Exclusion Criteria:

• physical or clinical limitations to deambulation

Outcomes:

• Functional capacity : Evaluation of the variation in the distance covered in a pre-determined time with a validated walking test (six minute walking test); Evaluation of the variation in the time needed to complete 5 cycles of the "sit-to-stand-to sit" test.
• Quality of Life : Score obtained by a validated questionnaire for dialysis patients (Kidney Disease Quality of Life instrument o KDQOL).
• Fatal and non-fatal events (cardiovascular and all-causes).
• All-cause hospitalizations.
• Vascular access survival. The power analysis was performed by calculating the sample size for each clinical outcome contemplated by the study protocol. The overall sample size of the trial is that portended by the calculation demanding the highest individuals numbers (that of the outcome "fatal and non fatal cardiovascular events" in our instance).

In a previous observational study by our group, the incident rate of fatal and non fatal cardiovascular events was at three years 25% (4). We hypothesised that the physical exercise will produce a 10% reduction in the hazard ratio of fatal cardiovascular events (hazard ratio: 0.70) as compared to that of the control group.

References:

• Mallamaci F, Tripepi G, Cutrupi S, Malatino LS, Zoccali C. Prognostic value of combined use of biomarkers of inflammation, endothelial dysfunction, and myocardiopathy in patients with ESRD. Kidney Int. 2005 Jun;67(6):2330-7. PMID: 15882276
• Kutner NG, Zhang R, Huang Y, Herzog CA. Cardiac rehabilitation and survival of dialysis patients after coronary bypass. J Am Soc Nephrol. 2006 Apr;17(4):1175-80. Epub 2006 Feb 15. PMID: 16481413
• Malagoni AM, Catizone L, Mandini S, Soffritti S, Manfredini R, Boari B, Russo G, Basaglia N, Zamboni P, Manfredini F. Acute and long-term effects of an exercise program for dialysis patients prescribed in hospital and performed at home. J Nephrol. 2008 Nov-Dec;21(6):871-8. PMID: 19034871
• Zoccali C, Tripepi G, Mallamaci F.Predictors of cardiovascular death in ESRD.Semin Nephrol. 2005 Nov;25(6):358-62

Inclusion criteria

• Patients on dialysis
• Dialysis vintage>6 mo.
• Age>18 aa.
• Signed informed consent
• Stable clinical conditions

Exclusion criteria

-any physical or clinical limitations to deambulation