The Association of Ambient Air Pollution With Dynamic Transitions of Cataract and Dementia: A UK Biobank Study

Background and Objectives

Air pollution has a detrimental effect on the risk of dementia and cataract. This study aimed to investigate the association of air pollution with the dynamic transitions of cataract and dementia.

Research Design and Methods

We enrolled 409,608 participants (mean age: 56.4 years; 45.9% male) free of cataract and dementia at baseline from the UK Biobank with follow-up until 30 September 2023. We estimated the annual average concentrations of particulate matter (PM) with aerodynamic diameter ≤ 2.5 μm (PM_2.5), ≤ 10 μm (PM₁₀), nitrogen dioxide (NO₂), and nitrogen oxides (NO_x) at 2010. We employed multi-state models to assess the association between air pollution and the dynamic transitions of cataract and dementia after adjusting for potential confounders.

Results

During a median follow-up of 14.5 years, 51,786 participants were diagnosed with cataracts, and 6068 with dementia. PM_2.5 showed the strongest association with the transitions from healthy to cataract (hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.04–1.06; p < 0.001), from healthy to dementia (HR, 1.05; 95% CI, 1.02–1.09; p = 0.002), from cataract to comorbidity (HR, 1.07; 95% CI, 1.00–1.15; p = 0.048), from healthy to death (HR, 1.03; 95% CI, 1.01–1.05; p < 0.001), and from cataract to death (HR, 1.06; 95% CI, 1.02–1.10; p = 0.007).

Conclusion and Implications

Our study suggested that the long-term exposure to air pollution was associated an increased risk of the transitions from health to incident cataract, dementia or the progression of both conditions. This implied the importance of implementing air pollution control strategies to prevent cataract and dementia.