Risk of Parkinson disease after organophosphate or carbamate poisoning.

AIMS: Parkinson disease (PD) is a common neurodegenerative disease. The aim of this study was to evaluate the risk of PD in patients with organophosphate (OP) or carbamate (CM) poisoning by using the Taiwan National Health Insurance Research Database. METHODS: We conducted a retrospective study involving a cohort of 45 594 patients (9128 patients with a history of OP or CM poisoning and 36 466 control patients) who were selected from the Taiwan National Health Insurance Research Database. The patients were observed for a maximum of 12 years to determine the rates of new-onset PD, and a Poisson regression model was used to identify the predictors of PD. The cumulative incidence of PD between the two cohorts was plotted through Kaplan-Meier analysis. RESULTS: During the study period, the incidence rate ratio (IRR) of PD in the OP or CM poisoning patients was 1.36-fold [95% confidence interval (CI)=1.26-1.47] higher than that in the control patients in the multivariable model. The absolute incidence of PD was the highest for the group aged ≥75 years in both cohorts (77.4 vs 43.7 per 10 000 person-years). However, the age-specific relative risk was higher for the group aged <50 years (adjusted IRR=3.88; 95% CI=3.44-4.39). CONCLUSION: Our results suggest that the likelihood of developing PD is greater in patients with OP or CM poisoning than in those without poisoning. OP or CM poisoning may be an independent risk factor for PD.

Decreased prevalence of dementia associated with statins: a national population-based study.

BACKGROUND AND PURPOSE: Dementia is a neurodegenerative disorder that presents a progressive decline in cognitive function and loss of short-term memory with age. Several studies have shown that statin, an oral lipid-lowering drug, may reduce the risk of developing dementia. The objective of this study is to explore the association between statin and the development of dementia. METHODS: The data analyzed in this study were retrieved from the National Health Insurance Research Database in Taiwan. The sample consisted of 123 300 patients ≥ 20 years of age, including 61 650 dementia patients with statin use and 61 650 patients without statin use who were eligible for inclusion in this study. Univariate and multivariate Cox proportional hazard regression analyses were performed to measure the effects of statin use on the risk of dementia. RESULTS: The beneficial effect of statin on dementia was significant after adjusting for sociodemographic factors and comorbidities (adjusted hazard ratio of 0.92, 95% confidence interval 0.86-0.98). The sex- and age-specific analysis of adjusted hazard ratios showed a higher beneficial effect from statin treatment in women than in men, and the effect became more significant with age. CONCLUSION: Statin therapy may help prevent the development of dementia, and both hydrophilic and lipophilic statins produce similar effects. However, the preventive characters and associated mechanisms must be further explored and identified.