More is not always better: Frequent dialysis does not markedly improve physical health

Some recent observational studies suggest that more frequent hemodialysis may prolong kidney failure patients' lives compared with conventional dialysis. If it does, what's the quality of that extra life? The additional treatments—which are time-consuming and take a considerable toll on patients—do not markedly improve patients' physical health, according to a study appearing in an upcoming issue of the Clinical Journal of the American Society Nephrology (CJASN).

Kidney failure, or end-stage kidney disease, afflicts more than 2 million people worldwide. Many of these individuals are on long-term hemodialysis and suffer from relatively poor physical health.

Researchers and clinicians have wondered whether increasing the frequency of dialysis treatments can improve or at least preserve kidney failure patients' overall physical capacity by reducing excess body fluid, improving their exercise ability, providing a better balance of nutrition, and preserving muscle mass, among other things.

To test this, Yoshio Hall, MD (University of Washington, Seattle) and his colleagues examined changes in physical health among patients enrolled in two studies: the Frequent Hemodialysis Network Daily and Nocturnal Trials, which randomized patients to receive either frequent (six times per week) or conventional (three times per week) dialysis for one year. All patients in the Daily Trial received treatments in a clinic while nearly all of those in the Nocturnal Trial received them at home, while they slept.

Among the major findings:

• Among the 245 patients in the Daily Trial, patients randomized to frequent compared with conventional dialysis experienced no significant change in physical performance, but they reported that they felt that their physical health and functioning had improved.
• Among the 87 patients in the Nocturnal Trial, patients who received frequent dialysis did not demonstrate better physical performance or report better physical health and functioning compared with patients who received conventional dialysis. Patients in both groups experienced improved physical health and functioning over the course of the year, though, perhaps due to the switch from clinical to home-based treatments.

"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," said Dr. Hall. "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," he added.