The purpose of this study is to determine whether hemodiafiltration, a new form of hemodialysis can improve sleep apnea in patients with end stage kidney disease.

Sleep apnea or breathing problems during sleep are frequent, occurring in 6% of the general population. However, more than half of all patients on dialysis suffer from breathing problems related to sleep. Sleep apnea is associated with high blood pressure, excessive sleepiness, fatigue, poor memory and concentration as well as depression in those with normal kidneys.

Hemodiafiltration is a new kind of dialysis that is more efficient at clearing toxins that accumulate in kidney failure. It has been used successfully in Europe for over 15 years. However, the effects of hemodiafiltration on sleep apnea in dialysis patients have never been assessed.

We are conducting a clinical trial to examine the effects of hemodiafiltration on sleep apnea in dialysis patients. Fifteen patients with sleep apnea, already on dialysis will be treated with hemodiafiltration 3 times a week, instead of their regular hemodialysis treatment for a period of 3 months. We will repeat sleep studies in these patients before and after the hemodiafiltration period and assess their quality of life.

We hope to decrease the severity of sleep apnea with hemodiafiltration. This could result in better sleep, improved energy level, mood, memory, concentration and blood pressure control in those afflicted by sleep apnea and on dialysis. Our findings would also give us better insight into the cause of sleep apnea in patients with end stage kidney disease.

Inclusion Criteria:

• Patients currently stable on a thrice weekly hemodialysis regimen for a minimum of 3 months
• Patients with vascular access and no contraindications to anticoagulation
• Presence of sleep-related breathing disorder defined as a mean apnea-hypopnea per hour of recording greater than 10 based on cardiorespiratory monitoring

Exclusion Criteria:

• Patients already on hemodiafiltration therapy
• Patients already on treatment for sleep disordered breathing.
• Patients with significant neuromuscular disease
• Patients with an expected lifespan < 1 year
• Patients unable to complete sleep related quality of life questionnaires and consent forms due to language barriers or dementia
• Patients with known substance abuse
• Patients with a respiratory disturbance index greater than 30 with active cardiovascular disease defined by unstable angina, myocardial infarction within 3 months or an Epworth sleepiness score greater than 15 while actively working in a stress situation (for example bus driver, taxi driver). These patients will be evaluated by a sleep specialist.
• Living further than 30 km from dialysis centre