When patients were switched from conventional dialysis to receiving it at night, the sleep apnea disappeared in six of the seven subjects. On average, the frequency of apnea episodes decreased to nine per hour, from 46 . Conventional dialysis has patients coming into the hospital for four hours, three times a week. However, in the very first nocturnal dialysis program started in Toronto seven years ago, patients receive their dialysis at home while they sleep. This means they get dialysis for a longer time and more frequently.
Patients are usually on the dialysis machine six to seven nights a week.
Dr. Pierratos is primary investigator of the nocturnal hemodialysis project and associate professor of medicine at the University of Toronto. He co-authored the paper with Dr. Hanly. Why a link between sleep apnea and renal failure exists is not fully known. Most patients in this study developed sleep apnea only after chronic renal failure had been established, Dr. Hanly and Dr. Pierratos said in their paper. Sleep apnea decreases daytime functioning and increases drowsiness, and may increase the risk of developing hypertension, coronary artery disease and stroke.