Restless legs syndrome does not affect 3-year mortality in hemodialysis patients

Uremic restless legs syndrome (RLS) has been related to an enhanced mortality of hemodialysis (HD) patients. In the general population studies of this association have yielded inconsistent results. The aim of the present study was to re-evaluate the relationship of RLS and mortality in HD patients.

We recorded the 3-year mortality in 579 HD patients after assessment for RLS symptoms. This population has been previously evaluated for the prevalence of RLS, according to the essential criteria of the International RLS Study Group. Mortality data were acquired from the national end-stage renal disease registry. Survival probability was calculated by the Kaplan-Meier method and analyzed by the log-rank test. For multivariate survival analysis, we implemented a Cox regression model.

During the 3-year follow-up, we documented 118 deaths. Mortality was 15.6% in patients with RLS and 22.3% in patients without RLS (p =  0.079). According to the Cox regression analysis, there was no significant association between RLS and 3-year mortality, either in an age- and gender-adjusted model (hazard ratio [HR] = 0.772, 95% confidence interval [CI] = 0.488-1.219, p = 0.267) or in a multivariate adjusted model (HR = 0.667, 95% CI = 0.417-1.069, p = 0.092).

Diagnosis of RLS according to the essential criteria of the International RLS Study Group does not seem to influence the 3-year mortality in HD patients. Our findings are in contrast to those in some previous reports, and reinforce the need for further studies of RLS and mortality in HD.