title: Constipation and risk of Parkinson's disease: A Danish population-based cohort study.
abstract: To examine long-term associations between constipation and Parkinson's disease (PD) in men and women, we conducted a population-based cohort study using prospectively collected registry data on hospital contacts for constipation and PD, stratified by follow-up time and sex.
  
  
  
  We linked Danish registries to construct a cohort of all patients in Denmark with an outpatient hospital diagnosis of constipation 1995-2012 and a matched general population comparison cohort. Using Cox regression, we computed hazard ratios (HRs) for PD and corresponding 95% confidence intervals (CIs), adjusting for potential confounders, stratified by sex and follow-up time.
  
  
  
  The 31,905 patients with constipation had a higher risk of PD than 159,092 comparison cohort members (adjusted (a) HR = 3.03, 95% CI 2.50-3.66), which was sustained to 11-15 years follow-up (aHR = 3.65, 95% CI 1.67-7.95). Increased risk was apparent in both sexes but stronger in men [aHR = 3.52 (2.67-4.64] than women [aHR = 2.64 (95% CI 2.02-3.44].
  
  
  
  In this large population-based cohort study, constipation was associated with sustained increased risk of a PD diagnosis, and the relative risk was higher for men than for women.
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Denmark. Electronic address: Elisabeth.svensson@clin.au.dk.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Svensson
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Denmark; Departments of Health Research & Policy (Epidemiology) and of Neurology & Neurological Sciences, Stanford University, Stanford, CA, USA.
authors.forename: Victor W
authors.initials: VW
authors.lastname: Henderson
authors.affiliation: Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Borghammer
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Denmark.
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Horváth-Puhó
authors.affiliation: Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Denmark.
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sørensen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003248:Constipation / Q000453:epidemiology*; D003718:Denmark; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology*; D012042:Registries / Q000706:statistics & numerical data*; D012306:Risk; D012737:Sex Factors; D055815:Young Adult
keywords: Constipation; Non-motor symptom; Parkinson’s disease; Risk factor