title: Association of olfactory dysfunction with risk for future Parkinson's disease.
abstract: OBJECTIVE
  Although olfactory dysfunction is commonly associated with Parkinson's disease (PD), it is not known whether such dysfunction can predate the onset of clinical PD in a community-based population. This study examines the association of olfactory dysfunction with future development of PD in Honolulu-Asia Aging Study cohort members
  
  
  METHODS
  Olfaction was assessed from 1991 to 1996 in 2,267 men in the Honolulu-Asia Aging Study aged 71 to 95 years who were free of clinical PD and dementia at the time of olfaction testing. Participants were followed for up to 8 years for incident PD RESULTS: In the course of follow-up, 35 men were diagnosed with PD (24.6/10,000 person-years). The average age at the time of diagnosis was 82.9 +/- 3.8 (range, 76-93) years, and the average time to a diagnosis was 4.0 +/- 1.9 (range, 1-8) years. During the first 4 years of follow-up, age-adjusted incidence of PD declined from 54.5/10,000 person-years in the lowest quartile of odor identification to 26.6, 8.2, and 8.4/10,000 person-years in the second, third, and fourth quartiles, respectively (p < 0.001 for trend). After adjustment for age and other potential confounders, the odds ratios for PD in the lowest quartile was 5.2 (95% confidence interval, 1.5-25.6) compared with the top two quartiles. This relation was not evident beyond 4 years of follow-up.
  
  
  CONCLUSIONS
  Impaired olfaction can predate clinical PD in men by at least 4 years and may be a useful screening tool to detect those at high risk for development of PD in later life.
authors: Veterans Affairs Pacific Islands Health Care System, University of Hawaii John A. Burns School of Medicine, Honolulu, HI 96819, USA. wross@phrihawaii.org
authors: G Webster
authors: GW
authors: Ross
authors: Helen
authors: H
authors: Petrovitch
authors: Robert D
authors: RD
authors: Abbott
authors: Caroline M
authors: CM
authors: Tanner
authors: Jordan
authors: J
authors: Popper
authors: Kamal
authors: K
authors: Masaki
authors: Lenore
authors: L
authors: Launer
authors: Lon R
authors: LR
authors: White
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001213:Asian / Q000706:statistics & numerical data; D001921:Brain / Q000503:physiopathology; D002454:Cell Differentiation / Q000502:physiology; D015331:Cohort Studies; D015897:Comorbidity; D018450:Disease Progression; D042241:Early Diagnosis; D006254:Hawaii / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008403:Mass Screening; D000857:Olfaction Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D009833:Olfactory Pathways / Q000503:physiopathology; D010300:Parkinson Disease / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors; D012903:Smell / Q000502:physiology