Delirium, genetic susceptibility and Parkinson's disease progression: a community- and UK biobank-based matched...

While various psychological factors increase Parkinson's disease (PD) risk, delirium's role remains unexplored. This study examined whether delirium is associated with PD incidence and identified potential modifying factors.

We conducted a matched cohort study using UK Biobank data, including 6,254 patients with first-time delirium and 31,270 matched unexposed individuals. Cox proportional hazards models assessed PD risk following delirium, evaluating effect modification by age, sex, education, BMI, depression, frailty, and polygenic risk scores.

During follow-up (median: 1,011 days for exposed vs 1,678 days for unexposed), 2% of delirium patients developed PD vs 1% of controls. Delirium was associated with significantly increased PD risk (HR: 3.97; 95% CI: 2.97-5.33). Education level significantly modified this association, with higher education linked to greater risk (College: HR 6.57; Non-college: HR 3.70). Age, sex, BMI, frailty, and polygenic risk scores did not significantly alter the association.

Delirium is a significant and potentially modifiable risk factor for PD, highlighting the clinical importance of its prevention and management, particularly in highly educated individuals.