Prevalence and Sleep Related Disorders of Restless Leg Syndrome in Hemodialysis Patients

BACKGROUND Despite being frequently described, Restless Leg Syndrome (RLS) in patients, who are on hemodialysis, is a common disease which, has not been well documented in Iran. OBJECTIVES The current study aimed to investigate the prevalence of RLS and its sleep disorders in Iranian patients on hemodialysis. PATIENTS AND METHODS In this multicenter cross sectional study, 397 consecutive patients on hemodialysis were evaluated by face-to-face interviews. RLS was diagnosed using the International RLS Study Group (IRLSS) criteria. In addition, three validated sleep disorder questionnaires (Insomnia Severity Index, Epworth sleepiness scale and Pittsburgh sleep quality index) were completed by the patients. RESULTS One hundred-twenty-six patients with RLS (31.7%; mean age 57.6 ± 15.4 years) participated in the current study. RLS mostly occurs in females (P < 0.001). RLS cases showed poorer quality of sleep (Pittsburgh Sleep Quality Index > 5, P = 0.001), higher scores of Epworth Sleepiness Scale (P < 0.001) and insomnia severity index (P = 0.001). Except thyroid gland dysfunction (P < 0.03, OR ≈ 2.50) and anti-hypertensive medications (P < 0.01, OR ≈ 1.7), there were no significant differences between age, duration of dialysis, etiology of renal insufficiency, intake of nicotine, alcohol or caffeine, and other associated comorbidities between the patients with and without RLS. CONCLUSIONS In the current study, prevalence of RLS was near the weighted-mean prevalence of other studies (mean 30%, range 8%t-52%). This is not just racial variability and may attribute to narrow or wide definition of the disease, plus variations of the prevalence recording time, and sometimes not using the standard criteria or standard interview.