Beta-adrenoceptor drugs and progression to Parkinson's disease milestones in a large pooled incident cohort.

Beta-adrenoceptor-blockers and agonists have been associated with an increased and decreased risk of Parkinson's disease (PD), respectively. We aimed to investigate whether these medications are linked to clinical heterogeneity and progression in PD. Longitudinal data from the Parkinson's Incident Cohorts Collaboration (n = 1107) were analysed. Baseline clinical status and progression to Hoehn & Yahr stage 3 (H&Y3) or dementia were compared in beta-blocker or beta-agonist users versus non-users of each drug. Baseline motor and cognitive variables were similar in beta-blocker users (n = 195) versus non-users and beta-agonist users (n = 68) versus non-users, following adjustment for relevant confounders. Beta-blocker users (n = 156) progressed faster to H&Y3 (p = 0.002), accounting for relevant confounders (Hazard Ratio (HR) = 1.538; p = 0.011), while beta-agonist users (n = 54) progressed similarly to non-users. Neither drug was associated with progression to dementia. These findings support the possibility that beta-adrenoceptor drugs may have potential in modifying aspects of PD progression. Further investigation is essential to identify any causative component in the relationship.