evaluation of electrostimulation program during dialysis sessions in chronic renal failure patients

Conditions: Chronic Renal Failure (CRF)

Summary: sport improves quality of life and health, decreasing cardiovascular risks and increasing effort tolerance. chronic renal failure (crf) induces many clinical and biological complications leading to less effort tolerance (strength and endurance). renal failure patients got also many cardiovascular risks : sedentarily lifestyle, hypertension (hta), diabetes, neuropathies, bone disorders, depression and sedentarity due to dialysis sessions. moreover, dialysis sessions three times a week induce the spiral of deconditioning. in order to counteract this, sport should be encourage in this specific hemodialysis population. the aim of this study is to evaluate electrostimulation program during dialysis sessions for 3 months. evaluation will be done using the test of 6-minute walk (6mwt). secondary aims will be evaluated: * muscular strength and quadriceps diameter * equilibrium * quality of life. * strength developed during maximal exercise test in a subgroup (patient undergoing dialysis in rennes center, about 40% of the total population) * nutritional intakes (quantitative and qualitative evaluation)

the primary outcome is the difference between distances during the 6 minutes walk test before and after the 3 month program between the stimulated and the non stimulated group. the secondary outcomes will be evaluated by maximum strength developed during the ergometry, limited by symptoms; maximal charge during muscular test; quadricipital diameter; time for the " timed up and go " test; quality of life scores. all those scores will be evaluated in the control and stimulated groups before and after the 3 month period. this is an open randomized controlled study. tests will be done by an investigator unaware of the stimulation group. the study is designed to detect a difference of 61 m (+/- 80 m) (6mwt) before and after stimulation in the stimulated group and 0 in the control group. this difference has been based on a pilot study with ergocycle in the same population and on literature in other populations (chronic respiratory failure or post cardiac surgery). we estimated that 70 patients would need to be enrolled in each group to provide 90% statistical power with a bilateral test.

Eligibility criteria:
inclusion criteria: * patients, \> 18 y/o, undergoing chronic hemodialysis since more than 3 months. * physical activity score (voorrips test) \<9.4 * patients clinically and hemodynamically stable. * no major drug or dialysis treatment changes since 2 weeks * written consent signed. exclusion criteria: * relative or absolute contraindication to ergotest (acc/aha, 2002) and/or physical reentrainment. * incapacity to practice the test of 6-minute walk (6mwt) or ergotest * clinical instability during hemodialysis sessions. * hb\<9g/dl despite medical treatment ; pas ≥180 mmhg et/ou pad ≥110 mmhg despite medical treatment ; * cardiac pace maker or defibrillator ; * pregnancy ; * recent cardiovascular events: cardiac failure less than 10 days before, instable angina, coronary angioplasty less than 10 days cardiac surgery less than 1 month, valvulopathy requiring surgery, myopericarditis, severe rhythm troubles despite medical treatment, stade iv arteriopathy. * bmi ≥ 30 kg/m² ; * anxiety and mental disorder * concomitant pathology leading to severe general status alteration. * patient participating to another medical study * electromyostimulation or effort entrainment program less than a month. * patients on renal transplantation awaiting list. * patient practicing sport ( response to voorips test)