Restless legs syndrome and arterial stiffness in pre-dialysis chronic kidney disease

Despite plenty of restless legs syndrome (RLS) studies conducted with hemodialysis patients, it has been scarcely studied in patients with predialysis chronic kidney disease (CKD). In the present study, we aimed to investigate the frequency of RLS in patients with nondialysis chronic kidney disease and explore the relationship between RLS with sleep quality, depression, pulse wave velocity (PWV), and clinical parameters. This cross-sectional study included 259 stage 3–5 predialysis CKD patients. The diagnosis of RLS was defined according to the diagnostic criteria defined by the international RLS study group. Beck depression inventory (BDI) was employed to assess depression while Pittsburgh Sleep Quality Index (PSQI) was employed to assess sleep quality. 41 patients (16%) were diagnosed with RLS. BDI and PSQI scores of patients with RLS were significantly higher than those without RLS (p = 0.01, p = 0.03, respectively). Pulse wave velocity (PWV) was significantly lower in patients with RLS (8.0 ± 1.8) than those without RLS (8.6 ± 1.9) (p = 0.05). Decrease in PWV and increase in BDI score demonstrated by multivariate analysis were shown as independent predictors of RLS development (ExpB = 1.266, p = 0.02 and ExpB = 0.957, p = 0.007 and p = 0.04, respectively). RLS is a significant problem in predialysis CKD patients and depression, and poor sleep quality is typical in these patients. Arterial stiffness is lower in these patients and any factors related to the pathophysiology of RLS might play important roles in modulating atherosclerosis.