Year: 2018
Type: article
Study design: Observational Study
Abstract: BACKGROUND: The aim of this paper is to investigate the causality of the inverse association between cigarette smoking and Parkinson's disease (PD). The main suggested alternatives include a delaying effect of smoking, reverse causality or an unmeasured confounding related to a low-risk-taking personality trait. METHODS: A total of 715 incident PD cases were ascertained in a cohort of 220 494 individuals from NeuroEPIC4PD, a prospective European population-based cohort study including 13 centres in eight countries. Smoking habits were recorded at recruitment. We analysed smoking status, duration, and intensity and exposure to passive smoking in relation to PD onset. RESULTS: Former smokers had a 20% decreased risk and current smokers a halved risk of developing PD compared with never smokers. Strong dose-response relationships with smoking intensity and duration were found. Hazard ratios (HRs) for smoking <20 years were 0.84 [95% confidence interval (CI) 0.67-1.07], 20-29 years 0.73 (95% CI 0.56-0.96) and >30 years 0.54 (95% CI 0.43-0.36) compared with never smokers. The proportional hazard assumption was verified, showing no change of risk over time, arguing against a delaying effect. Reverse causality was disproved by the consistency of dose-response relationships among former and current smokers. The inverse association between passive smoking and PD, HR 0.70 (95% CI 0.49-0.99) ruled out the effect of unmeasured confounding. CONCLUSIONS: These results are highly suggestive of a true causal link between smoking and PD, although it is not clear which is the chemical compound in cigarette smoking responsible for the biological effect.
DOI: 10.1093/ije/dyy230
Authors: Valentina Gallo, Paolo Vineis, Mariagrazia Cancellieri, Paolo Chiodini, Roger A Barker, Carol Brayne, Neil Pearce, Roel Vermeulen, Salvatore Panico, Bas Bueno-de-Mesquita, Nicola Vanacore, Lars Forsgren, Silvia Ramat, Eva Ardanaz, Larraitz Arriola, Jesper Peterson, Oskar Hansson, Diana Gavrila, Carlotta Sacerdote, Sabina Sieri, Tilman Kühn, Verena A Katzke, Yvonne T van der Schouw, Andreas Kyrozis, Giovanna Masala, Amalia Mattiello, Robert Perneczky, Lefkos Middleton, Rodolfo Saracci, Elio Riboli
Institutions: Queen Mary University of London, London School of Hygiene & Tropical Medicine, Blizard Institute, Imperial College London, University of Campania "Luigi Vanvitelli", Azienda USL di Bologna, University of Cambridge, Utrecht University, University Medical Center Utrecht, Federico II University Hospital, University of Naples Federico II, University of Malaya, National Institute for Public Health and the Environment, Istituto Superiore di Sanità, Umeå University, Azienda Ospedaliero-Universitaria Careggi, University of Florence, Instituto de Salud Pública de Navarra, Navarre Institute of Health Research, Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública, Basque Government, Biogipuzkoa Health Research Institute, Lund University, Instituto Murciano de Investigación Biosanitaria, Italian institute for Genomic Medicine, Piedmont Reference Center for Epidemiology and Cancer Prevention, Fondazione IRCCS Istituto Nazionale dei Tumori, German Cancer Research Center, National and Kapodistrian University of Athens, Hellenic Health Foundation, German Center for Neurodegenerative Diseases, Munich Cluster for Systems Neurology, Ludwig-Maximilians-Universität München, Centre international de recherche sur le cancer
Language: English
Subfield: Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,514
Funders: World Health Organization, Deutsches Krebsforschungszentrum, Wellcome Trust, Cancer Research UK, National Institute for Health and Care Research, British Heart Foundation, European Commission, Institut National de la Santé et de la Recherche Médicale, Bundesministerium für Bildung und Forschung, Ligue Contre le Cancer, Vetenskapsrådet, Associazione Italiana per la Ricerca sul Cancro, Norges Forskningsråd, Deutsche Krebshilfe, Medical Research Council, World Cancer Research Fund, Instituto de Salud Carlos III
OpenAlex ID: W2904709665