Previous studies have shown consistently increased likelihood of dementia or mild cognitive impairment diagnoses in people with higher air pollution exposure history, but evidence has been less consistent for associations with cognitive test performance. We estimated the association between baseline neighbourhood-level exposure to airborne pollutants (particulate matter and nitrogen oxides) and (1) cognitive test performance at baseline and (2) cognitive score change between baseline and follow-up, in the UK Biobank cohort. 86,759 adults were assessed at baseline in 2010, and 2,913 were followed up after around 3 years. Initial analyses indicated small but consistent associations between higher air pollutant exposure and lower cognitive performance. However, after taking account of a range of key confounders, associations were inconsistent in direction and of very small magnitude. Analyses of cognitive change scores did not show evidence of associations with pollution levels. The findings indicate that in this sample, which is five-fold larger than any previous cross-sectional study in this field, the association between air pollution exposure and cognitive performance was weak. Ongoing follow-up of the UK Biobank cohort will allow investigation of longer-term associations into old age, including longitudinal tracking of cognitive performance and new dementia diagnoses.
Cognitive outcomes in people with behavioural and brain disorders within UK Biobank
This research will comprise a series of cross-sectional studies of baseline cognitive data from the UK Biobank resource. Complex statistical models will be used to estimate the relationship between key risk factors (e.g. medical status and genetic markers) and cognitive performance, while taking into account the additional influence of other demographic, social and lifestyle factors.
This research aims to understand the variation of cognitive performance in adults with behavioural and brain disorders such as depression, bipolar disorder and multiple sclerosis. Cognitive impairment is common and functionally disabling in patients with behavioural and brain disorders, but it remains poorly understood at an individual level. This research investigates the nature and extent of cognitive impairment in adults with behavioural and brain disorderes groups compared to healthy controls, and develops multivariate models to explore the relationship between cognitive performance and medical status, demographic and lifestyle factors, and genetic markers. This cross-sectional research aims to contribute to the refinement of hypotheses regarding risk factors for cognitive impairment, providing a foundation for future longitudinal research focused on understanding, preventing and treating cognitive impairment in these groups.
Cullen et al (2017) 'The cognitive footprint of psychiatric and neurological conditions: Cross-sectional study in the UK Biobank cohort', Acta Psychiatrica Scandinavica, 135:593-605. DOI: 10.1111/acps.12733
Cullen et al. Cross-sectional and longitudinal analyses of outdoor air pollution exposure and cognitive function in UK Biobank. Sci Rep 8, 12089 (2018). https://doi.org/10.1038/s41598-018-30568-6
|Lead investigator:||Breda Cullen|
|Lead institution:||University of Glasgow|