title: Appendectomy may delay Parkinson's disease Onset.
abstract: BACKGROUND
  Alpha-synuclein (α-Syn) is particularly abundant in the vermiform appendix, which makes this structure an anatomical candidate for the initiation of Parkinson's disease (PD) pathology. We hypothesized that history of appendectomy might affect PD clinical onset.
  
  
  METHODS
  A total of 295 PD patients enrolled in a comprehensive observational study were asked about past history of appendectomy. Cox's regression, with a time-dependent covariate, explored the effects of appendectomy on age at PD onset.
  
  
  RESULTS
  Thirty-four patients (11.5%) had appendectomy before PD onset. There was no significant effect of appendectomy on age at PD onset for the entire cohort (P = 0.153). However, among patients with late onset (≥55 years), we found evidence that those with past appendectomy had more years of life without PD symptoms than patients without appendectomy (P = 0.040). No association was found for the young-onset group (P = 0.663).
  
  
  CONCLUSIONS
  An apparent relationship was observed between appendectomy and PD onset in the late PD cohort.
authors.affiliation: Serviço de Neurologia, Centro Hospitalar do Porto, Porto, Portugal.|Unidade Multidisciplinar de Investigação Biomedica, Instituto Ciências Biomedicas Abel Salazar, Universidade do Porto, Porto, Portugal.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Mendes
authors.affiliation: Serviço de Neurologia, Centro Hospitalar do Porto, Porto, Portugal.|Unidade Multidisciplinar de Investigação Biomedica, Instituto Ciências Biomedicas Abel Salazar, Universidade do Porto, Porto, Portugal.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Gonçalves
authors.affiliation: Serviço de Neurologia, Centro Hospitalar do Porto, Porto, Portugal.|Unidade Multidisciplinar de Investigação Biomedica, Instituto Ciências Biomedicas Abel Salazar, Universidade do Porto, Porto, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Vila-Chã
authors.affiliation: Unidade Multidisciplinar de Investigação Biomedica, Instituto Ciências Biomedicas Abel Salazar, Universidade do Porto, Porto, Portugal.
authors.forename: Inês
authors.initials: I
authors.lastname: Moreira
authors.affiliation: Unidade Multidisciplinar de Investigação Biomedica, Instituto Ciências Biomedicas Abel Salazar, Universidade do Porto, Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Fernandes
authors.affiliation: Serviço de Neurologia, Centro Hospitalar do Porto, Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Damásio
authors.affiliation: CINTESIS, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.|Screening and Test Evaluation Program, Sydney School of Public Health, University of Sydney, Sydney, Australia.
authors.forename: Armando
authors.initials: A
authors.lastname: Teixeira-Pinto
authors.affiliation: Serviço de Neurologia, Centro Hospitalar do Porto, Porto, Portugal.|Serviço de Neuropatologia, Centro Hospitalar do Porto, Porto, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Taipa
authors.affiliation: Serviço de Neurologia, Centro Hospitalar do Porto, Porto, Portugal.
authors.forename: António Bastos
authors.initials: AB
authors.lastname: Lima
authors.affiliation: Serviço de Neurologia, Centro Hospitalar do Porto, Porto, Portugal.|Unidade Multidisciplinar de Investigação Biomedica, Instituto Ciências Biomedicas Abel Salazar, Universidade do Porto, Porto, Portugal.
authors.forename: Sara
authors.initials: S
authors.lastname: Cavaco
mesh_terms: D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001062:Appendectomy; D001065:Appendix / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000378:metabolism / Q000517:prevention & control*; D051844:alpha-Synuclein / Q000378:metabolism*
chemical_list: D051844:alpha-Synuclein
keywords: Parkinson's disease; appendectomy; disease onset; vermiform appendix; α-synuclein