Study Finds Morning Dialysis Patients Live Longer

Elderly patients undergoing regular dialysis for kidney failure live longer if they get their treatment in the morning, a new study has found.

Patients with kidney failure must undergo dialysis to clear waste products from the blood. No previous research has been done into whether the time of day at which dialysis is performed has any effect on patient survival, according to Dr. Donald L. Bliwise of Emory University in Atlanta, Georgia, and colleagues.

To investigate, Bliwise's team followed 242 patients aged 60 and older for 11 years. The study participants included 167 patients who had dialysis in the morning, and 75 who had the procedure in the afternoon.

Morning dialysis patients lived, on average, about 1 year and 3 months longer than the patients treated in the afternoon, Bliwise and colleagues report.

When other factors that could affect survival, such as whether or not a patient had diabetes or heart disease, were taken into account, the researchers found morning dialysis cut the risk of death by about 30%.

The authors note that timing has been shown to influence the effectiveness of certain medical treatments. For example, in certain cancers, chemotherapy is much more effective when given in the early morning.

While the reason for the survival advantage to morning dialysis remains unclear, the fact that morning patients are more likely to sleep during the procedure may play a role, co-author Dr. Nancy Kutner explained.

``Previous studies have shown that dialysis during sleep may be more effective,'' she says. Another possibility, the researchers suggest, is that dialysis may be less effective when performed during the afternoon.

``More research needs to be conducted to identify if morning hemodialysis is more beneficial,'' she added.

Every year in the US, more than 300,000 patients receive treatment for kidney failure and roughly 20% of these patients die annually, the report notes.