Restless legs syndrome (RLS) is a sleep disorder thought to be related to iron stores and dopamine receptors of basal ganglia of brain. It occurs more commonly in patients with chronic renal failure (CRF), iron deficiency, and some other conditions. Its incidence in a few reports of patients with CRF from Asia varies from 1% to 60%. We studied this syndrome in patients with CRF and analyzed the effect of various parameters possibly involved in the etiology of RLS.
We investigated 194 patients (116 males and 78 females) with CRF diagnosed in Tabriz University Hospital using a structured questionnaire evaluating details of sleep, RLS, sleep apnea and other sleep disorders, and drug history. Daytime sleepiness was investigated with a modified Epworth Sleepiness Scale. Also a detailed laboratory investigation including serum, iron, ferritin, and PTH levels were performed.
56 (28.9 %) patients, 27(23.1 %) men and 29 (37.2%) women had symptoms compatible with RLS. (p= 0.04). There was no significant difference on the mean levels of hemoglobin (9.7 ± 0.18 versus 10.1 ± .31; p= 0.71) serum iron (72.2 ± 3.63versus 74.3± 6.66; p= 0.87), and serum ferritin (684 ± 97.4 versus 519 ± 138; p= 0.65) in patients with CRF who had RLS and those did not. There was a statistically significant difference daytime sleepiness in patient with CRF who did and did not have RLS ( 5.92±0.76 versus 2.95±0.34; p=0.0001).
RLS syndrome is a common disorder in patients with CRF in Asian population of Azarbaydjan province of Iran.. Unlike general population in patients with CRF presence of RLS has no relationship with serum ferritin, serum iron level, or degree of anemia. These patients had poor quality of sleep that is at least partly related to the presence of RLS.
RLS in patient with CRF is not related to serum ferritin or iron levels or degree of anemia and treatment on this direction is not expected to be as efficacious as patients without CRF.
Khalil Ansarin, University grant monies Supported by a gran from Tuberculosis and Lung Research Center, Tabriz University of Medical Sciences, Tabriz, Iran