Approved research

Associations between air quality, regional brain volumes, cognitive functioning, and neuropsychiatric outcome in middle-aged and older adults: a cross-sectional study

Lay summary

In this study, we aim to identify and elucidate associations in adults between exposure to air pollution and cognitive function, mood disorders, and brain structure. Exposure to air pollution has been associated with increased risk for respiratory and cardiovascular disease, and recent work suggests an association between exposure to air pollution and worsened cognitive function in children and adults and possibly dementia. In that air pollution has been associated with cognitive function, we hypothesize that it might be associated with the mood disorders depression and bipolar disorder. In addition, air pollution has been associated with abnormal brain volume in children and adults. Air pollution might be associated with cognitive function via damage to the protective blood-brain barrier or inflammation. We propose to use data from the UK Biobank to investigate further the relationship between exposure to air pollution and cognitive and mood outcomes and brain volumes. To identify factors that might influence any associations between air pollution and cognition, mood disorders, and brain volume, we plan to investigate the potential effects of several medical and social variables, such as age, sex, and educational attainment. If this application is successful, we anticipate completing the project in six months after receiving the data. Given the numbers of people including children worldwide exposed to air pollution and findings showing possible associations between exposure to air pollution and cognitive development, cognitive function, and brain volume, additional information characterizing these associations in large, controlled studies are vital for public interest and global health, particularly considering increasing global urbanization and subsequent exposure to air pollution. Identification of risk and protective factors is also important in better understanding the effects of air pollution on cognitive and mental health.

Scope extension:

With the availability of data about exposure to infectious disease, we would like to expand the scope of our study to include exposure to infectious diseases as a possible predictor of cognitive function, brain volume, and neuropsychiatric outcome in line with our overarching research goal of identifying factors associated with neurocognitive decline. Accordingly, we would like to add an additional research question to our current project: What is the association between exposure to air pollution and infectious disease and volume of multiple brain regions, and cognition in middle-aged and older adults? Additionally, we would like to investigate possible interactions between exposure to air pollution and infectious-disease exposures in predicting cognitive function and brain structure. In that previous findings have suggested possible associations between exposure to certain infectious disease and cognitive decline (Nimgaonkar et al,. 2016) and dementia (Itzhaki and Lathe, 2018), the recently available data about exposure to infectious disease enable the further exploration of associations between infectious disease.