title: Quitting smoking: an early non-motor feature of Parkinson's disease?
abstract: BACKGROUND
  Epidemiological studies report a 60-70% reduced risk of Parkinson's disease (PD) in smokers as compared to non-smokers. However, relationships between former smoking and PD have been poorly investigated.
  
  
  METHODS
  We recruited 116 de novo PD subjects, and investigated current, former and never smoking, and reasons for smoking cessation among former smokers. Two hundred and thirty-two controls were matched by Propensity Score.
  
  
  RESULTS
  PD subjects and controls were found to be current smokers (7.7 vs. 39.6%), former smokers (43.9 vs. 6.5%) and never smokers (48.2 vs. 53.9%). Logistic regression showed that current smokers were less likely to have PD (p < 0.001; OR: 0.22; 95% CI: 0.10-0.46), while former smokers were more likely to have PD (p < 0.001; OR: 7.6; 95% CI: 4.09-15.75), as compared to never smokers. Fifty-one PD patients reported quitting smoking before PD diagnosis (mean time since cessation 9.4 ± 7.3 years). Most important reasons to quit smoking in PD group were illness different from PD (26 subjects, 51.0%), knowledge of the harmful effects of smoking (24 subjects, 47.0%), and physician's advice (1 subject, 2.0%).
  
  
  CONCLUSIONS
  The reduced prevalence of current smokers among PD subjects as compared to healthy controls is consistent with previous findings, suggesting a possible neuroprotective effect of smoking. However, it could be due, at least in part, to the increased prevalence of former smokers among PD patients, that were more prone to quit smoking as compared to healthy controls. We suggest that smoking cessation could be an early preclinical condition occurring in PD.
authors.affiliation: Department of Neuroscience, Reproductive Science and Odontostomatology, Federico II University, Naples, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Moccia
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom; Department of Neurological and Movement Sciences, University of Verona, Policlinico Borgo Roma, Verona, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Erro
authors.affiliation: Center for Neurodegenerative Diseases (CEMAND), Neuroscience Section, Department of Medicine, University of Salerno, 84131, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Picillo
authors.affiliation: Center for Neurodegenerative Diseases (CEMAND), Neuroscience Section, Department of Medicine, University of Salerno, 84131, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Vassallo
authors.affiliation: IDC Hermitage Capodimonte, Naples, Italy; Department of Motor Sciences, University Parthenope, Naples, Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Vitale
authors.affiliation: IDC Hermitage Capodimonte, Naples, Italy.
authors.forename: Katia
authors.initials: K
authors.lastname: Longo
authors.affiliation: IDC Hermitage Capodimonte, Naples, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Amboni
authors.affiliation: Neuropsychology Laboratory, Department of Psychology, Second University of Naples, Caserta, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Santangelo
authors.affiliation: Department of Primary Care and Public Health, Imperial College, London, United Kingdom; Department of Public Health, Federico II University, Naples, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Palladino
authors.affiliation: Department of Public Health, Federico II University, Naples, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Nardone
authors.affiliation: Department of Public Health, Federico II University, Naples, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Triassi
authors.affiliation: Center for Neurodegenerative Diseases (CEMAND), Neuroscience Section, Department of Medicine, University of Salerno, 84131, Italy. Electronic address: pbarone@unisa.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Barone
authors.affiliation: Center for Neurodegenerative Diseases (CEMAND), Neuroscience Section, Department of Medicine, University of Salerno, 84131, Italy.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Pellecchia
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology* / Q000523:psychology*; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation / Q000706:statistics & numerical data*
keywords: Non-motor; Parkinson; Premotor; Quitting; Smoking