Risk of fracture amongst patients with Parkinson's disease and other forms of parkinsonism.

Introduction: Postural instability, a core feature of parkinsonism, leads to an increased risk of falls and fractures. However, the risk of fracture has not been assessed in an incident cohort of Parkinson's disease and atypical parkinsonism.

Objectives: We determined the absolute and relative fracture risk and predictive variables in a prospective incident cohort of parkinsonian patients and controls.

Methods: Fracture data for 326 incident parkinsonian cases (198 Parkinson's disease, 128 atypical parkinsonism) and 261 controls was recorded annually in the Parkinsonism Incidence in North-East Scotland study. Incidence rates were determined for all fractures and major fractures. Kaplan-Meier curves were used to determine time to first fracture for each group. Stepwise, multivariate Cox regression analysis was used to identify risk factors for fracture in parkinsonian patients.

Results: Mean age at recruitment was 74.5 years in all parkinsonian patients (age at diagnosis) and 75 years in controls. The incidence of any fracture was 5.5 (95% CI 4.3-7.0) and 2.0 (1.3-2.9)/100 participant-years for the parkinsonian and control groups respectively, whilst for major fractures due to falls it was 4.2 (3.2-5.5) and 1.4 (0.9-2.2)/100 participant-years respectively. Independent predictors for fractures in parkinsonian patients were osteoporosis, female gender and falling during the follow up period. There was no difference in fracture rates between those with Parkinson's disease and atypical parkinsonism.

Conclusion: The fracture rate in parkinsonism from the time of diagnosis (about 5% per year) is over three times greater than controls. Fracture risk should be routinely assessed in all parkinsonian patients.