Restless legs syndrome in maintenance hemodialysis patients: an epidemiologic survey in Hefei

To investigate the prevalence of restless legs syndrome (RLS) in maintenance hemodialysis (MHD) patients and its possible influencing factors.

MHD patients were consecutively enrolled from five hemodialysis centers in Hefei. Clinical, demographics, and laboratory data were recorded from December 2013 to March 2014. RLS diagnosis scale, Zung Self-Rating Depression Scale (SDS), Zung Self-Rating Anxiety Scale (SAS), Pittsburgh Sleep Quality Index (PSQI), and kidney disease and quality of life (KDQOLTM-36) were used for analysis.

A total of 269 MHD patients (81 women, 188 men) were enrolled, among which 39 patients were diagnosed as RLS. The median duration of dialysis therapy was 33 months and the prevalence of RLS was 14.5%. Compared with RLS-negative patients, RLS-positive patients had lower hemoglobin level (98.67 ± 13.50 vs 106.34 ± 17.75, P = 0.011) and higher alkaline phosphatase concentration [131.0 (98.0, 226.0) vs 94.0 (69.8, 157.5), P = 0.001]. The multivariate logistic regression showed that high hemoglobin level (OR 0.975, 95% CI 0.956-0.995, P = 0.015) was a protective factor for RLS, while high alkaline phosphatase (OR 1.003, 95% CI 1.001-1.005, P = 0.018) was an independent risk factor for RLS. RLS patients had significantly higher PSQI scores (P < 0.001), reduced subjective sleep quality (P < 0.001), increased sleep latency (P < 0.007), shorter sleep duration (P < 0.001), lower sleep efficiency (P = 0.001), higher sleep disturbances (P < 0.001), and increased daytime dysfunction (P = 0.019).

Our findings demonstrated that the prevalence of RLS was 14.5% in Hefei. High hemoglobin level was a protective factor for RLS, and high alkaline phosphatase was an independent risk factor. RLS affects many aspects of quality of life and sleep quality, which may contribute to the presence of depression and anxiety.