Risk factors associated with Parkinson’s disease: An 11-year population-based South Korean study

Background: The etiology of parkinsonism involves gene and environment interaction, but the identity of most causal factors remains unknown. Investigating the distribution and characteristics of the condition is important for identifying further etiologic factors and planning public health policies. Objectives: To validate various known risk factors of Parkinsonism and to establish basic information to formulate public health policy by using an 11 year followup cohort model. Methods: This population based nationwide study was performed using the National Health Insurance Database of reimbursement claims of the Health Insurance Review and Assessment Service of South Korea data on regular health check-ups in 2003 and 2004, with 11 years` followup. Results: We identified 7,746 patients with Parkinsonism. Old age, hypertension, diabetes, depression, anxiety, taking statin medication, high body mass index, nonsmoking, nonalcohol drinking, and low socioeconomic status were each associated with an increase in the risk of Parkinsonism (fully adjusted Cox proportional hazards model: hazard ratio 1.259, 95% confidence interval 1.194~61485;1.328 for hypertension, hazard ratio 1.255, 95% confidence interval 1.186~61485;1.329 for diabetes, hazard ratio 1.554, 95% confidence interval 1.664~61485;1.965 for depression, hazard ratio 1.808, 95% confidence interval 1.462~61485;1.652 for anxiety, and hazard ratio 1.157, 95% confidence interval 1.072~61485;1.250 for taking statin medication). Conclusions: In our study, old age, depression, anxiety, and nonsmoker status were found to be risk factors of Parkinsonism, concordant with previous studies. However, sex, hypertension, diabetes, taking statin medication, nondrinking of Alcohol, and lower socioeconomic status have not been described as risk factors previously and need further verification in future studies.