Association of ambient air pollution with cognitive functioning and structural brain damage: The Maastricht Study

Abstract

AbstractBackgroundDementia prevention poses one of the biggest challenges to our ageing society (1,2). Next to individual modifiable risk factors, shared environmental risk factors have been linked to dementia risk. Exposure to air pollution has been identified as a new candidate risk factor which on a population level carries more risk than well‐established risk factors such as hypertension and type‐2 diabetes (1). This study aimed to investigate the association between exposure to air pollutants with cognitive functioning and markers of structural brain damage next to and above individual risk factors.MethodCross‐sectional data from the population‐based cohort (N = 4,154; mean age 59.27±8.54 years, 50.12% women) of The Maastricht Study (3) was used and matched to address‐based data from the Geoscience andHealth Cohort Consortium of average exposure to particulate matter (<2.5mg and <10mg), NO2 and soot over the years 2013‐2018. Cognitive functioning was assessed through a neuropsychological test battery. Standardized volumes of grey matter, white matter, cerebrospinal fluid, and presence of cerebral small vessel disease were derived from 3‐Tesla MRI. Individual risk factors were added as one covariate, using the validated Lifestyle for Brain Health score (4). Binary logistic and multiple linear regression analyses tested the associations between air pollutants and the outcome measures. Likelihood‐ratio tests were performed to compare the extensive models.ResultWe found a curvilinear association relating particulate matter exposure in the mid to higher range to lower grey matter and higher cerebrospinal fluid volume, independent of age, sex, education, and LIBRA score. There was no association between air pollutant exposure and cognitive functioning or markers of cerebral small vessel disease.ConclusionIn this population‐based cohort, average to high exposure to particulate matter was related to an increase in markers of brain atrophy, showing important implications for environmental and public health policymaking.