title: Risk of Injurious Fall and Hip Fracture up to 26 y before the Diagnosis of Parkinson Disease: Nested Case-Control Studies in a Nationwide Cohort.
abstract: BACKGROUND
  Low muscle strength has been found in late adolescence in individuals diagnosed with Parkinson disease (PD) 30 y later. This study investigated whether this lower muscle strength also may translate into increased risks of falling and fracture before the diagnosis of PD.
  
  
  RESULTS
  Among all Swedish citizens aged ≥50 y in 2005, two nested case-control cohorts were compiled. In cohort I, individuals diagnosed with PD during 1988-2012 (n = 24,412) were matched with up to ten controls (n = 243,363), and the risk of fall-related injuries before diagnosis of PD was evaluated. In cohort II, individuals with an injurious fall in need of emergency care during 1988-2012 (n = 622,333) were matched with one control (n = 622,333), and the risk of PD after the injurious fall was evaluated. In cohort I, 18.0% of cases and 11.5% of controls had at least one injurious fall (p < 0.001) prior to PD diagnosis in the case. Assessed by conditional logistic regression analysis adjusted for comorbid diagnoses and education level, PD was associated with increased risks of injurious fall up to 10 y before diagnosis (odds ratio [OR] 1.19, 95% CI 1.08-1.31; 7 to <10 y before diagnosis) and hip fracture ≥15 y before diagnosis (OR 1.36, 95% CI 1.10-1.69; 15-26 y before diagnosis). In cohort II, 0.7% of individuals with an injurious fall and 0.5% of controls were diagnosed with PD during follow-up (p < 0.001). The risk of PD was increased for up to 10 y after an injurious fall (OR 1.18, 95% CI 1.02-1.37; 7 to <10 y after diagnosis). An important limitation is that the diagnoses were obtained from registers and could not be clinically confirmed for the study.
  
  
  CONCLUSIONS
  The increased risks of falling and hip fracture prior to the diagnosis of PD may suggest the presence of clinically relevant neurodegenerative impairment many years before the diagnosis of this disease.
authors.affiliation: Geriatric Medicine, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden.|Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Nyström
authors.affiliation: Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Nordström
authors.affiliation: Geriatric Medicine, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Nordström
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D005544:Forecasting; D006620:Hip Fractures / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis*; D011159:Population Surveillance / Q000379:methods*; D012042:Registries; D012307:Risk Factors
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