Restless legs syndrome in dialysis patients: a meta-analysis

Restless legs syndrome (RLS) occurs frequently in dialysis patients. However, it remains elusive regarding the risk factors for RLS onset in dialysis patients.

A meta-analysis was performed to investigate the association between clinical measures (age, gender, diabetes mellitus or DM etc.) and RLS in dialysis patients. We searched electronic databases from January 1990 to February 2014 to identify studies that met inclusion criteria. Either a fixed-effects or, in the presence of heterogeneity, a random-effects model was used to calculate the pooled odds ratios (ORs)/standard mean differences (SMDs) and their corresponding confidence intervals (CIs).

Twenty-three studies were included in this study. Dialysis patients with RLS demonstrated significantly higher OR of DM compared with non-RLS in Asians (OR: 1.238, 95% CI: 1.032-1.484, P = 0.021). Dialysis patients with RLS showed markedly lower level of hemoglobin (Hb)/iron compared with non-RLS in overall populations/Caucasians (SMD: -0.178/-0.104, 95% CI: -0.352/-0.206 to -0.004/-0.002, P = 0.045/0.045; SMD: -0.283/-0.158, 95% CI: -0.552/-0.304 to -0.013/-0.012, P = 0.04/0.034). No differences of female populations, age, duration of dialysis, body mass index (BMI), blood urea nitrogen (BUN), creatinine, albumin, phosphorus, parathyroid hormone (PTH), and calcium were observed between dialysis patients with RLS and non-RLS in overall populations, Caucasians and Asians. No evidence of publication bias was observed.

Our findings indicate that dialysis patients with DM are nearly 24% more susceptible to RLS in Asians. Decreased Hb/iron is a risk factor for RLS onset in dialysis patients in overall populations including Caucasians.