title: Prevalence and associated comorbidities of restless legs syndrome (RLS): Data from a large population-based door-to-door survey on 19176 adults in Tehran, Iran.
abstract: BACKGROUND
  Discrepancies have been reported in the prevalence rate of restless legs syndrome (RLS) among different ethnic groups and geographic populations. Furthermore, there are disagreements on determinant factors and associated comorbidities of RLS. We aimed to estimate prevalence of RLS and investigate its associated comorbid conditions and risk factors in a large population-based door-to-door survey.
  
  
  METHODS
  Following a multistage random sampling from the households lived in 22 urban districts of Tehran, Iran, 19176 participants with ≥30 years of age were recruited. Trained surveyors filled study checklist consisting of baseline characteristics, risk factors and comorbidity profile and the International RLS Study Group (IRLSSG) diagnostic criteria through face-to-face interviews.
  
  
  RESULTS
  In total, 1580 individuals were positively screened for RLS resulting in a standardized prevalence rate of 60.0/1000. There was a gradual increase in RLS prevalence by advancing age, however, sex difference disappeared after adjustment. Parkinsonism [adjusted odds' ratio (adj-OR) = 7.4 (95% CI: 5.3-10.4)], peripheral neuropathy [adj-OR = 3.7 (95% CI: 3.3-4.1)], subjective cognitive impairment (SCI) [adj-OR = 3.1 (95% CI: 2.7-3.4)], acting out dreams [adj-OR = 2.8 (95% CI: 2.5-3.2)], hyposmia [adj-OR = 2.5 (95% CI: 2.2-2.9)], active smoking [adj-OR = 1.5 (95% CI: 1.3-1.9)] and additional number of cardiometabolic diseases associated with higher risk of RLS [adj-OR = 1.6 (95% CI: 1.2-2.3)].
  
  
  CONCLUSIONS
  Our findings showed that neuro-cognitive co-morbidities such as parkinsonism, peripheral neuropathy, SCI, acting out dreams and hyposmia as well as cardio-metabolic risk factors and diseases were independent determinants of RLS. It is recommended to screen individuals with either these comorbid conditions for RLS or the ones with RLS for the accompanying diseases.
authors.affiliation: Division of Clinical geriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Karolinska Institutet, Stockholm, Sweden.|Department of Neurology and Neurosurgery, Faculty of Medicine, McGill University, Montreal General Hospital, Montreal, Québec, Canada.|Firoozgar Clinical Research Development Center (FCRDC), Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed-Mohammad
authors.identifier: http://orcid.org/0000-0001-9255-9351
authors.initials: SM
authors.lastname: Fereshtehnejad
authors.affiliation: Medical Student Research Committee (MSRC), Mental Health Research Center, Tehran Psychiatry Institute, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Rahmani
authors.affiliation: Medical Student Research Committee (MSRC), Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahdiyeh
authors.initials: M
authors.lastname: Shafieesabet
authors.affiliation: Medical Student Research Committee (MSRC), Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahshid
authors.initials: M
authors.lastname: Soori
authors.affiliation: Division of Clinical geriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Karolinska Institutet, Stockholm, Sweden.|Iranian Research Center on Aging, University of Social Welfare and Rehabilitation, Tehran, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Delbari
authors.affiliation: Firoozgar Clinical Research Development Center (FCRDC), Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran.|Neurology Department, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Motamed
authors.affiliation: Division of Clinical geriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Karolinska Institutet, Stockholm, Sweden.|Department of Geriatric Medicine, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Lökk
mesh_terms: D000368:Aged; D015897:Comorbidity; D005260:Female; D006306:Health Surveys; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012148:Restless Legs Syndrome / Q000453:epidemiology*; D012959:Socioeconomic Factors