title: Iron metabolism and the risk of restless legs syndrome in an elderly general population--the MEMO-Study.
abstract: BACKGROUND
  Low iron and ferritin blood levels have been observed in patients with Restless Legs Syndrome (RLS) with an inverse relation between symptom severity and ferritin level. All reports are based on single cases or case series of hospitalized patients or those from outpatient clinics. No data from population studies are available.
  
  
  METHODS
  Cross-sectional study examining the associations between 5 measures of iron metabolism and RLS in an elderly general population in southern Germany. All 365 participants, aged 65 to 83 years, were examined neurologically and interviewed using standardized questions addressing the four minimal criteria for RLS. Iron, ferritin, transferrin, soluble transferrin receptor and C-Reactive Protein were analysed with standard laboratory methods.
  
  
  RESULTS
  The prevalence of Restless Legs Syndrome in this population was 9.8 %. Odds Ratios associated with Restless Legs were significantly increased in the fourth quintile of iron (OR 3.08 95 % CI 1.02-9.29) and transferrin saturation (OR 5.68 95 % CI 1.18-27.26) compared with the third (middle) quintile. Increases in the first (lowest) quintile of both measures were not or borderline significant. No associations with ferritin and soluble transferrin receptor were found.
  
  
  CONCLUSIONS
  No evidence was found that iron or ferritin deficiency are a major cause of RLS in this population study. The results support the hypothesis that changes in the complex regulation of iron metabolism contribute to the occurence of RLS.
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Muenster, Domagkstr. 3, 48149 Muenster, Germany. bergerk@uni-muenster.de
authors.forename: Klaus
authors.initials: K
authors.lastname: Berger
authors.forename: Arnold
authors.initials: A
authors.lastname: von Eckardstein
authors.forename: Claudia
authors.initials: C
authors.lastname: Trenkwalder
authors.forename: Andreas
authors.initials: A
authors.lastname: Rothdach
authors.forename: Ralf
authors.initials: R
authors.lastname: Junker
authors.forename: Stephan Karl
authors.initials: SK
authors.lastname: Weiland
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D005293:Ferritins / Q000097:blood* / Q000172:deficiency / Q000378:metabolism; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007501:Iron / Q000097:blood* / Q000378:metabolism; D000090463:Iron Deficiencies; D016015:Logistic Models; D008297:Male; D008568:Memory / Q000502:physiology; D009017:Morbidity; D016017:Odds Ratio; D011990:Receptors, Transferrin / Q000097:blood; D012148:Restless Legs Syndrome / Q000097:blood* / Q000453:epidemiology; D012307:Risk Factors
chemical_list: D011990:Receptors, Transferrin; D005293:Ferritins; D007501:Iron