Restless legs syndrome enhances cardiovascular risk and mortality in patients with end-stage kidney disease undergoing long-term haemodialysis treatment.

BACKGROUND Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterized by paraesthesia, dysaesthesia and the irresistible urge to move the legs especially at night. Its prevalence is much higher among dialysis patients at 12 to 62% compared to 3 to 9% in the general population. Here, we investigated the association between RLS and cardiovascular events risk and laboratory parameters in end-stage kidney disease (ESKD) patients on dialysis. METHODS One hundred ESKD patients undergoing haemodialysis were enrolled in an 18-month prospective observational study. The main outcomes were the associations of RLS with new cardiovascular events and cardiovascular mortality. RESULTS RLS affected 31% of the study population. It was associated with female gender, gradual reduction in residual diuresis, lower albumin (P = 0.039) and inflammation, but not the dialysis parameters Kt/V and URR. During observation, 47% of patients experienced new cardiovascular events (64.5% with and 39.1% without RLS; P = 0.019). New cardiovascular events increased with severity of RLS [intermittent (I-RLS) vs continuous (C-RLS)]. Mortality was 20.0% in all patients, 32.3% in those with and 14.5% in patients without RLS (P = 0.04). In patients with I-RLS, mortality was 23.8% compared to 55.6% in patients with C-RLS (P = 0.014). Multivariate analysis confirmed the relationship between RLS and mortality. CONCLUSIONS This study confirmed the high prevalence of RLS among dialysis patients and the associations between the severity of RLS and the risk of new cardiovascular events and higher short-term mortality.