title: Association of restless legs syndrome with oxidative stress and inflammation in patients undergoing hemodialysis.
abstract: BACKGROUND
  Restless legs syndrome (RLS) is a common comorbidity in patients undergoing hemodialysis, but clinical factors predictive of RLS risk and severity have not been identified. The aims of this multicenter cross-sectional study were to document RLS prevalence and severity in patients undergoing hemodialysis and to identify associated risk factors.
  
  
  METHODS
  One-hundred and fifty-nine stable patients on maintenance hemodialysis were enrolled (113 men, 46 women; mean age: 68 ± 11 years; mean duration of dialysis: 54 ± 60 months). Diagnosis of RLS was based on the criteria proposed by the International Restless Legs Syndrome Study Group (IRLSSG), and RLS severity was assessed using the IRLSSG Severity Scale. Potential factors associated with RLS and IRLSSG Severity Scale score were assessed by univariate and multivariate regression analyses.
  
  
  RESULTS
  RLS affected 22% of the study population. The RLS subgroup had a significantly longer duration of hemodialysis and higher cardiothoracic ratio compared to the non-RLS subgroup. The RLS subgroup also had significantly higher serum levels of high-sensitivity C-reactive protein, interleukin-6, ferritin, N-terminal pro-B-type natriuretic peptide, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), and a significantly lower transferrin saturation level compared to the non-RLS subgroup, suggesting a chronic inflammatory state and associated oxidative stress in comorbid patients. Serum 8-OHdG level was an independent risk factor for high IRLSSG Severity Scale score.
  
  
  CONCLUSIONS
  This study confirms the high prevalence of RLS among hemodialysis patients and identifies the oxidative stress marker serum 8-OHdG as a significant independent predictor of RLS severity. Further studies are needed to identify detailed risk factors and the pathophysiological role of oxidative stress in RLS.
authors.affiliation: Department of Nephrology, Keiai Hospital, Tokyo 173-0036, Japan.
authors.forename: Terumi
authors.initials: T
authors.lastname: Higuchi
authors.affiliation: Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan. Electronic address: abe.masanori@nihon-u.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Abe
authors.affiliation: Department of Nephrology, Keiai Clinic, Tokyo 173-0036, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Mizuno
authors.affiliation: Department of Nephrology, Keiai Hospital, Tokyo 173-0036, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Yamazaki
authors.affiliation: Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan.
authors.forename: Masari
authors.initials: M
authors.lastname: Moriuchi
authors.affiliation: Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Oikawa
authors.affiliation: Department of Nephrology, Keiai Hospital, Tokyo 173-0036, Japan.
authors.forename: Erina
authors.initials: E
authors.lastname: Okawa
authors.affiliation: Department of Cardiology, Keiai Hospital, Tokyo 173-0036, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ando
authors.affiliation: Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Okada
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000097:blood; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D015995:Prevalence; D006435:Renal Dialysis / Q000009:adverse effects*; D012148:Restless Legs Syndrome / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine
keywords: 8-Hydroxy-2′-deoxyguanosine; Hemodialysis; N-terminal pro-B-type natriuretic peptide; Oxidative stress; Restless legs syndrome