Prospective Study of Lung Function with Prodromal, Clinical Parkinson's Disease, and Mortality

Background: The association of lung function with the risk of developing prodromal and clinical-diagnosed Parkinson's disease (PD) and with the risk of mortality among individuals with PD remains unknown. Objective: To prospectively examine the associations of lung function with the risk of prodromal, clinical-diagnosed PD, and PD-related mortality in participants of the UK Biobank. Methods: Included were 452,518 participants free of PD at baseline. Baseline lung function, including forced expiratory volume in 1-s (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), and FEV1/FVC ratio, was assessed. Eight prodromal features were measured using self-reported diagnoses, hospital admission, and primary care data. Incident PD cases were identified using linkages with hospital admission, death register, and self-report. Vital status and date of death were provided by the UK National Health Service (NHS) and the NHS Central Register. We used Cox proportional hazard models to evaluate these associations. Results: Poor lung function was associated with higher risk of PD in a dose-response relationship: the adjusted hazard ratio comparing the lowest vs. the highest lung function quintile was 1.18 (95% CI, 1.02- 1.37) for FEV1, 1.14 (95% CI, 0.99- 1.29) for FVC, and 1.23 (95% CI, 1.08- 1.41) for PEF (p-trend <0.05 for all). Similar results were obtained for risk of prodromal PD and mortality among individuals with PD. Conclusions: The current study showed that individuals with poor lung function had a high future risk of prodromal and clinical PD and a higher rate of PD-related mortality.