Most patients in the overnight group reported an increase in appetite. They gained weight, and their serum albumin levels increased. Many were able to return to work and reported improved job performance and better cognitive function.

More frequent and longer dialysis regimens are a promising alternative to addressing the “unacceptably high” risk of death among dialysis patients, Dr. Ok said. Although home dialysis may be an ideal approach, it is not always an option for many patients.

Previous studies of thrice-weekly overnight HD have shown impressive results, with 10-year survival rates as high as 75%. This new study is the first prospective, controlled investigation to compare the results of eight-hour vs. four-hour HD performed in a dialysis center.

“I was partly surprised when I observed that almost all the patients adapted well enough to sleep during dialysis at the center,” Dr. Ok told Renal & Urology News. “It happened in just one month. I want to believe that longer night dialysis will be performed more in the near future and in many countries.”

Dr. Ok noted that the study had some important limitations. Assignment to the two dialysis strategies was not random and, with an average age of 45 years, the patients were younger than the general dialysis population. Few older patients were willing to switch to overnight HD. In addition, the follow-up was relatively short. Still, given the clear superiority of eight-hour dialysis, he does not think the results would be different with a longer period of observation.

His study findings should convince physicians, patients, and health authorities of the benefit of longer HD in terms of decreased morbidity and mortality.