Femur Fractures in Parkinsonism: Analysis of a National Sample Cohort in South Korea

BACKGROUND AND PURPOSE Falling with a femur fracture is a serious event that negatively affects the quality of life of elderly individuals as well as patients with parkinsonism. This study investigated the association between parkinsonism and femur fracture and compared the risk of femur fracture between subjects with and without parkinsonism. METHODS This study examined a population-based matched cohort constructed using the National Sample Cohort data set, which comprises approximately one million subscribers to medical insurance and aid in South Korea. Subjects with parkinsonism during 2003-2013 were identified as the exposed group, and up to five individuals matched for age, sex, and index years were identified as the controls for each parkinsonism subject. The risk of femur fracture for parkinsonism was evaluated using Cox regression. RESULTS The incidence of femur fracture according to age, sex, and body mass index varied significantly between subjects with parkinsonism and controls (p<0.001). The presence of parkinsonism was associated with a higher risk of femur fractures for males [hazard ratio (HR)=2.85, 95% confidence interval [CI]=1.87-4.34], subjects younger than 65 years (HR=2.89, 95% CI=1.64-5.11), and underweight subjects (HR=3.90, 95% CI=1.82-8.35). The adjusted HR for femur fracture with parkinsonism was highest within 2 years of the disease diagnosis (HR=3.10, 95% CI=2.12-4.53). CONCLUSIONS Our study found that the presence of parkinsonism is more strongly related to femur fracture in males, and increases the influence of traditional risk factors on femur fracture. It is necessary to consider how factors associated with the amount of ambulatory activity-even in an early diagnosed state-can play an important role in femur fracture in subjects with parkinsonism.