More Frequent Dialysis Does Not Improve Physical Health

Lara C. Pullen, PhD

March 16, 2012

March 16, 2012 — Frequent (6 times per week) in-center hemodialysis improves self-reported physical health and functioning, but has no significant effect on objective measures of physical performance when compared with conventional (3 times per week) in-center hemodialysis. Frequent in-home nocturnal hemodialysis does not improve objective physical performance or self-reported physical health compared with conventional in-home nocturnal hemodialysis.

Yoshio Hall, MD, from the University of Washington in Seattle, and colleagues published the result of 2 randomized clinical trials online March 15 in the Clinical Journal of the American Society of Nephrology.

"Frequent hemodialysis as currently practiced may improve the lives of some but is not a cost-effective or practical solution to improving the physical health of most patients with end-stage kidney disease," Dr. Hall commented in a news release. "Faced with rising numbers of persons with progressive chronic kidney disease worldwide, we need to broadly consider innovative strategies beyond manipulating the dose of dialysis to substantially improve or preserve the physical capacity of patients with end-stage kidney disease."

Some recent observational studies have suggested that more frequent hemodialysis may prolong the lives of patients with kidney failure. Researchers hypothesized that frequent hemodialysis might preserve a patient's overall physical capacity by reducing excess body fluid, improving the ability to exercise, providing a better balance of nutrition, and preserving muscle mass.

In the current study, Dr. Hall and colleagues assessed both objective physical performance and patient assessments of physical health and functioning in individuals who were randomly assigned to receive either conventional hemodialysis or frequent hemodialysis. Patients were enrolled in either the Frequent Hemodialysis Network (FHN) Daily Trial (245 patients) or the Nocturnal Trial (87 patients).

Patients with kidney failure experience a low baseline physical performance, health, and functioning. When physical performance was assessed by the short physical performance battery (SPPB), the FHN Daily Trial found no difference between patients randomly assigned to frequent compared with conventional in-center hemodialysis (adjusted mean change, −0.20 ± 0.19 vs −0.41 ± 0.21; P = .45). The SPPB measures primarily lower extremity function.

The self-reported outcomes for patients in the FHN Daily Trial were mixed. When measured with the RAND-36 physical health composite score, patients who received frequent in-center hemodialysis reported improved physical health compared with those receiving conventional dialysis (3.4 ± 0.8 vs 0.4 ± 0.8; P = .009). However, when measured by the RAND-36 physical functioning subscale, the difference of 4.5 between the groups did not reach statistical significance. Moreover, improvements in self-reported outcomes were not seen in patients in the Nocturnal Trial.

Rachel Fissell, MD, from the Cleveland Clinic in Ohio, spoke with Medscape Medical News about the article. She explained that, "this is a very well done study.... This study speaks with authority."

Dr. Fissell described the patient-reported results as encouraging and wondered whether there is a potential for objective measures of improved health, especially with a larger sample size. She noted that the Nocturnal Trial, in particular, may have been underpowered to see improvements (both objective and self-reported).

Kidney failure is on the rise and currently affects 2 million people worldwide. Many of these individuals are receiving long-term hemodialysis and experience relatively poor physical health. The authors emphasize that it is important to find strategies to improve the overall physical health of patients undergoing dialysis, as this may improve related factors such as lifestyle, health-related quality of life, and longevity.

Dr. Fissell agreed, "For our patients, the quality of their life is as important as their survival."

The trials were supported by the National Institutes of Health, National Institutes of Diabetes and Digestive and Kidney Diseases, the Centers for Medicare and Medicaid Services, and the National Institutes of Health Research Foundation. Dr. Hall has received research support from Satellite Healthcare's Norman Coplon Extramural grant program. Other authors have received research support from Dialysis Clinic Inc, Satellite Healthcare’s Norman Coplon Extramural grant program, and Baxter Healthcare; are employed by DaVita Inc; and have consulted for Merck, Sigma-Tau, Baxter Healthcare, Amgen Inc, and DaVita Inc. One author is a member of the board of directors of Satellite Healthcare and the Scientific Advisory Board of DaVita Inc and has consulted for Amgen Inc. Dr. Fissell has disclosed no relevant financial relationships.

Clin J Am Soc Nephrol. Published online March 15, 2012. Abstract