Increased risk of Parkinson disease in patients with carbon monoxide intoxication: a population-based cohort study.

The present study evaluated the association of carbon monoxide intoxication (COI) with Parkinson disease (PD).A total of 9012 adults newly diagnosed with COI were enrolled in this study as the COI cohort. The control (non-COI) cohort, comprising 36,048 participants, was matched for each COI patient according to age, sex, and the year of hospitalization. We calculated the hazard ratios (HR) and 95% confidence intervals by using a Cox proportional hazards regression model.The overall incidence of PD (per 10,000 person-year) in the COI and non-COI cohorts was 27.4 and 2.53, respectively. After adjustment for age, sex, and comorbidities, the COI patients exhibited a 9.08-fold increased risk for PD. The COI patients without comorbidity exhibited a significantly higher risk of PD (adjusted HR = 15.8) than did the COI patients without comorbidity (adjusted HR = 4.15). Patients with COI and receiving hyperbaric oxygen therapy exhibited a 14.3-fold increased risk of PD; the adjusted HR of patients who did not receive hyperbaric oxygen treatment was increased 7.97-fold.The risk of PD increased in the COI patients and the significance increased in young people. COI is a crucial factor leading to PD.