099 IMPROVEMENT OF RESTLESS LEGS SYNDROME AFTER RENAL TRANSPLANTATION IN CHILEAN PATIENTS WITH CHRONIC RENAL FAILURE

Abstract

Introduction: Restless legs syndrome (RLS) is a common cause of sleep disturbance that is frequently experienced by patients on dialysis suffering from chronic renal failure (CRF). Previous studies have described a reduction in RLS symptomatology after successful renal transplantation. However, the underlyingmechanism is not fully understood, and there are no local studies regarding this subject. Objective: This study aimed to evaluate the prevalence of RLS in patients with CRF on dialysis, to assess the improvement of symptoms after renal transplantation and to analyze laboratory parameters related to changes in symptomatology. Methods: We conducted a retrospective study on patients suffering from CRF on dialysis who were subjected to renal transplantation procedures. A standardized survey was applied for RLS diagnosis, according to the International RLS Study Group criteria, and the severity of the symptoms was evaluated before and after transplantation by use of ad-hoc intensity measurement scores. Multiple laboratory parameters were evaluated preand post-transplantation. Results: A total of 58 patients subjected to renal transplantation were evaluated, with an average age of 44 years (range, 18-72 years), of which 30 were males and 28 were females. Of these patients, 16 (28%), 5 females and 11 males with an average age of 45 years (range, 24-69 years), met the diagnostic criteria for RLS. The RLS mean severity score pre-transplantation was 23.7 (10-35) and 1.4 after transplantation (0-7) (p<0.001). Of the RLS group, 75% presented complete remission of symptoms after transplantation, and 25% (4/16) showed significant improvement. The average time in which this improvement was observed was 5.4 weeks. This reduction in symptomatology was related to an improvement in serum phosphate level and renal function (p<0.001); improvement was also seen for hematocrit and parathyroid hormone (PTH) levels (p<0.002 and p<0.05, respectively). Conclusions: Patients suffering from CRF treated with dialysis have a high prevalence of RLS. Patients with CRF and RLS subjected to renal transplantation showed a significant reduction of their symptomatology (100% in our series), and in most of the cases, complete recovery was observed. Similar to results described in international reports, this improvement after transplantationwas associatedwith an improvement in hematocrit, renal function and serum levels of phosphate and PTH. Nevertheless, the specific biological process underlying this improvement is still not fully understood.