title: Environmental risk factors for REM sleep behavior disorder: a multicenter case-control study.
abstract: OBJECTIVE
  Idiopathic REM sleep behavior disorder is a parasomnia characterized by dream enactment and is commonly a prediagnostic sign of parkinsonism and dementia. Since risk factors have not been defined, we initiated a multicenter case-control study to assess environmental and lifestyle risk factors for REM sleep behavior disorder.
  
  
  METHODS
  Cases were patients with idiopathic REM sleep behavior disorder who were free of dementia and parkinsonism, recruited from 13 International REM Sleep Behavior Disorder Study Group centers. Controls were matched according to age and sex. Potential environmental and lifestyle risk factors were assessed via standardized questionnaire. Unconditional logistic regression adjusting for age, sex, and center was conducted to investigate the environmental factors.
  
  
  RESULTS
  A total of 694 participants (347 patients, 347 controls) were recruited. Among cases, mean age was 67.7 ± 9.6 years and 81.0% were male. Cases were more likely to smoke (ever smokers = 64.0% vs 55.5%, adjusted odds ratio [OR] = 1.43, p = 0.028). Caffeine and alcohol use were not different between cases and controls. Cases were more likely to report previous head injury (19.3% vs 12.7%, OR = 1.59, p = 0.037). Cases had fewer years of formal schooling (11.1 ± 4.4 years vs 12.7 ± 4.3, p < 0.001), and were more likely to report having worked as farmers (19.7% vs 12.5% OR = 1.67, p = 0.022) with borderline increase in welding (17.8% vs 12.1%, OR = 1.53, p = 0.063). Previous occupational pesticide exposure was more prevalent in cases than controls (11.8% vs 6.1%, OR = 2.16, p = 0.008).
  
  
  CONCLUSIONS
  Smoking, head injury, pesticide exposure, and farming are potential risk factors for idiopathic REM sleep behavior disorder.
authors: Department of Neurology, McGill University, Montreal General Hospital, Montreal, Canada. ron.postuma@mcgill.ca
authors: R B
authors: RB
authors: Postuma
authors: J Y
authors: JY
authors: Montplaisir
authors: A
authors: A
authors: Pelletier
authors: Y
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authors: Dauvilliers
authors: W
authors: W
authors: Oertel
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authors: Iranzo
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authors: Ferini-Strambi
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authors: Arnulf
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authors: Hogl
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authors: Manni
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authors: Miyamoto
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authors: Mayer
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authors: Stiasny-Kolster
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authors: Puligheddu
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authors: Jennum
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authors: Sonka
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authors: Santamaria
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authors: Fantini
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authors: Zucconi
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authors: Leu-Semenescu
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authors: Frauscher
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authors: Terzaghi
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authors: Miyamoto
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authors: Cochen De Cock
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mesh_terms: D000368:Aged; D000438:Alcohols / Q000009:adverse effects; D016022:Case-Control Studies; D003069:Coffee / Q000009:adverse effects; D016001:Confidence Intervals; D004522:Educational Status; D004777:Environment; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009790:Occupations; D016017:Odds Ratio; D017286:Polysomnography; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis / Q000209:etiology*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012907:Smoking; D011795:Surveys and Questionnaires; D013662:Tea / Q000009:adverse effects
chemical_list: D000438:Alcohols; D003069:Coffee; D013662:Tea