Traditional Chinese Medicine Might Reduce Risk of Dementia in Patients with Parkinson’s disease: A Population-based Nested Case-control Study

Background Patients who have Parkinson’s disease (PD) comorbid with dementia is common. With the prolonged life expectancy, dementia is gradually becoming prevalent and affects most patients’ life qualities. However, the efficacy of current treatments in dementia of Parkinson’s disease is limited. Previous studies indicated the potential roles of Traditional Chinese Medicine (TCM) in treating dementia, yet its effects in preventing dementia from Parkinson’s patients are unknown.Methods This case–control study was nested within a national health insurance database of patients over 50 years old with newly diagnosed Parkinson’s disease from year 2000 to 2010. Among these PD patients, dementia and non-dementia groups were discussed respectively in terms of the duration of taking TCM (≥ 90 days versus < 90 days), age (50–64 versus ≥ 65) and gender.Results The risk of dementia in patients with Parkinson's disease is decreased by using TCM for < 90 days and ≥ 90 days, especially in the group who took TCM for more than 90 days. The use of TCM significantly reduces the risk of dementia in the subgroups of age ≥ 65 years, female patients using TCM for both < 90 days and ≥ 90 days, and male patients using TCM for < 90 days. Overall, we can see the protection tendency among all of the target population under TCM use.Conclusions The results showed that there is a significant reduction of nearly 38% in the risk of dementia for patients with Parkinson’s disease after the usage of Traditional Chinese Medicine. The beneficial effects for using TCM ≥ 90 days in women age ≥ 65 years are most prominent.Trial registration The study data were acquired from the Taiwan’s National Health Insurance (NHI) Research Database. The NHI-claimed data provide clinical information for population-based epidemiologic research. This study was approved by the Institutional Review Board of Chung Shan Medical University Hospital.