title: Incidence of restless legs syndrome and its correlates.
abstract: BACKGROUND
  Restless legs syndrome (RLS) is a common sensorimotor disorder whose incidence is not known. The aim of the study was to determine the incidence and correlates of RLS in a population-based sample.
  
  
  METHODS
  We obtained data from the Tucson Cohort of the Sleep Heart Health Study, a prospective multicenter study. This cohort included 535 participants aged ≥ 40 years, who answered questions regarding RLS on the 2002 and 2006 sleep surveys. For this study, RLS was defined as the presence of all 4 International RLS Study Group criteria, with symptoms occurring ≥ 5 days/month and associated with at least moderate distress.
  
  
  RESULTS
  Mean age of the predominantly Caucasian (90.8%) participants on the 2002 survey was 59.8 ± 9.7 years; 52.2% were women. RLS prevalence was 4.1% in 2002 and 7.7% in 2006. The yearly incidence of RLS was 1.7% (6.6% over 4 years). Multivariate analyses demonstrated that estrogen use (OR = 2.5, 95% CI: 1.17-5.10) and self-reported obstructive lung disease (OR = 2.8, 95% CI: 1.37-5.83) were independent risk factors predicting incident RLS. Incident RLS was associated with higher prevalence of insomnia (26.5% vs. 7.6%, p = 0.001), increased sleepiness (38.2% vs. 22%, p = 0.036); and higher sleeping pill use in 2006 (23.5% vs. 9.7%, p = 0.019).
  
  
  CONCLUSIONS
  The incidence of RLS in this population sample was 1.7% per year. Use of estrogen and history of obstructive lung disease were associated with a significantly higher incidence of RLS. RLS, in turn, was associated with insomnia and increased sleepiness.
authors.affiliation: Southern Arizona VA HealthCare System, 3601 S 6th Ave, Tucson, Arizona 85723, USA. budhirajap@yahoo.com
authors.forename: Pooja
authors.initials: P
authors.lastname: Budhiraja
authors.forename: Rohit
authors.initials: R
authors.lastname: Budhiraja
authors.forename: James L
authors.initials: JL
authors.lastname: Goodwin
authors.forename: Richard P
authors.initials: RP
authors.lastname: Allen
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.forename: Brian B
authors.initials: BB
authors.lastname: Koo
authors.forename: Stuart F
authors.initials: SF
authors.lastname: Quan
mesh_terms: D004967:Estrogens / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications; D012148:Restless Legs Syndrome / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D012307:Risk Factors; D012890:Sleep / Q000502:physiology; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
chemical_list: D004967:Estrogens