Restless legs syndrome in patients on maintenance hemodialysis and peritoneal dialysis

BACKGROUND: Restless legs syndrome (RLS) is highly frequent among uremic patients; however, little is known about RLS risk factors in these patients. We evaluated the frequency of RLS and associated risk factors in Iranian patients on maintenance hemodialysis (HD) and peritoneal dialysis (PD). METHODS: Ninety patients on maintenance HD (n=45) and PD (n=45) were included from two medical centers. Diagnosis of RLS was based on the International Restless Legs Syndrome Study Group criteria, confirmed by the validated Cambridge-Hopkins questionnaire. Patients were tested for iron state, folate, vitamin B-12, kidney function and electrolytes. RESULTS: Patients included 53 males and 37 females with the mean age of 54.2 +/- 15.2 years and disease duration of 5.3 +/- 4.5 years. RLS was diagnosed in 26.6% of the patients (35.1% in females vs. 20.7% in males, p = 0.019). RLS was more frequent in HD than PD patients (35.5% vs. 17.7%, p = 0.048), and in those with positive family history of RLS (37.5% vs. 4.5%, p < 0.001). Based on multivariate analysis, female gender [odds ratio (OR) = 6.67], being on HD (OR = 15.9), positive family history (OR = 19.1), higher body mass index (OR = 1.19), and higher serum transferrin (OR = 1.04) and lower total iron-binding capacity (OR = 0.96) levels were associated with risk of RLS. CONCLUSIONS: RLS was frequent in patients on maintenance dialysis and female gender, family history of RLS, being on HD, body mass index and iron deficiency were associated with the risk of RLS. Further studies are required for better understanding of RLS pathophysiology and possible treatments in uremic patients.