Prognostic value of restless legs syndrome in hemodialysis patients: a systematic review and meta-analysis

Background: Previous studies have revealed that restless legs syndrome (RLS) not only is frequently prevalent in dialysis patients but also increases the risk of death in dialysis patients, especially in hemodialysis (HD) patients. However, inconsistent results also still exist, having attracted confusion and discussion. Owing to mixed and inconclusive results, we conducted to perform the comprehensive meta-analysis to evaluate the potential prognostic value of RLS in HD patients. Materials and methods: We conducted a systematic literature search using electronic databases (PubMed, Ovid, Embase and Web of Science) to identify relevant studies reporting on all-cause mortality and cardiovascular (CV) events in HD patients suffering from RLS. We searched the literature published up to December 5, 2016, or earlier. We used both fixed-and random-effects models to calculate the overall effect estimate. An I-2>50% indicates at least moderate statistical heterogeneity. A sensitivity analysis and subgroup analysis were performed to find the origin of heterogeneity. Results: A total of four studies including 1,839 patients found that there was no significant association between RLS and all-cause mortality (hazard ratio [HR]: 1.649; 95% confidence interval [CI]: 0.778-3.496) and CV events (HR: 0.863; 95% CI: 0.600-1.127) in HD patients. Heterogeneity among the studies was observed for all-cause mortality (I-2=80.7%, P=0.001). Conclusion: Our meta-analysis suggests that there was no significant effect of RLS on all-cause mortality and CV events in HD patients. Therefore, large-scale and well-designed studies are needed to validate the association between RLS and the risk of death in HD patients.