title: Gout and the risk of Parkinson's disease: a cohort study.
abstract: OBJECTIVE
  Several studies have suggested that higher serum uric acid levels lead to a lower risk of Parkinson's disease (PD) because uric acid exerts antioxidant effects on neurons. Our objective was to examine the relationship between gout and the risk of PD in persons age > or = 65 years.
  
  
  METHODS
  We conducted a population-based cohort study using the British Columbia Linked Health Database and PharmaCare data (i.e., prescription drug data for those age > or = 65 years). We compared incidence rates of PD between 11,258 gout patients and 56,199 controls matched on age, sex, date of gout diagnosis, and length of medical record. Cox proportional hazards models were used to estimate the relative risk (RR) of PD, adjusting for age, sex, prior comorbid conditions, and use of diuretics and nonsteroidal antiinflammatory drugs.
  
  
  RESULTS
  Over an 8-year median followup, we identified 1,182 new cases of PD. Compared with individuals without gout, the multivariate RR of PD among those with gout was 0.70 (95% confidence interval [95% CI] 0.59-0.83). In subgroup analyses, the inverse association was similarly present in both sexes and was evident among those who did not use diuretics (RR 0.66, 95% CI 0.54-0.81), but not among diuretic users (RR 0.80, 95% CI 0.58-1.10, P for interaction 0.35).
  
  
  CONCLUSIONS
  Our population-based data provide evidence for a protective effect of gout on the risk of PD and support the purported protective role of uric acid.
authors.affiliation: Arthritis Research Centre of Canada and University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Mary
authors.initials: M
authors.lastname: De Vera
authors.forename: M Mushfiqur
authors.initials: MM
authors.lastname: Rahman
authors.forename: James
authors.initials: J
authors.lastname: Rankin
authors.forename: Jacek
authors.initials: J
authors.lastname: Kopec
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Hyon
authors.initials: H
authors.lastname: Choi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000502:physiology; D001955:British Columbia / Q000453:epidemiology; D016022:Case-Control Studies; D015331:Cohort Studies; D004232:Diuretics / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006073:Gout / Q000097:blood* / Q000150:complications*; D006801:Humans; D015994:Incidence; D008297:Male; D015999:Multivariate Analysis; D010300:Parkinson Disease / Q000453:epidemiology* / Q000517:prevention & control; D016016:Proportional Hazards Models; D012307:Risk Factors; D014527:Uric Acid / Q000097:blood*
chemical_list: D000975:Antioxidants; D004232:Diuretics; D014527:Uric Acid