Air pollution and plasma amyloid beta levels in an older cohort

Abstract

TPS 732: Neurological effects in adults, Exhibition Hall, Ground floor, August 27, 2019, 3:00 PM - 4:30 PM Background: Accumulation of amyloid beta (Aβ) proteins are central to development of Alzheimer’s disease (AD). Air pollution has been implicated in AD through its potential to cause neuroinflammation, microglia activation and white matter abnormalities. To date, no epidemiologic studies have examined the association between air pollution and this important biomarker of AD. Methods: The Ginkgo Evaluation of Memory Study (GEMS) is a longitudinal cohort of older adults (age 75 and older) recruited from four sites across the United States. Fine particulate matter (PM2.5), course particles (PM10) and nitrogen dioxide (NO2) were predicted from a national universal kriging model which estimated annual average pollutant levels at participant’s residential address one years prior to baseline visit. Both Aβ 1-40 and Aβ 1-42 were measured at baseline (years 2000-2001) and again in 2008 in plasma blood samples using ELISA. We modeled Aβ 1-40 and Aβ 1-42 separately and the ratio Aβ 1-42/Aβ 1-40 using linear regression adjusted for age, race, gender, site, education, neighborhood disadvantage, ApoE4 allele and cystatin-c. Results: Over 2800 participants had valid Aβ data at baseline. Preliminary cross-sectional results suggest an interquartile range (IQR) increase in PM2.5, PM10 and NO2 was associated with higher levels of Aβ 1-40 but not Aβ 1-42. A 3 µg/m3 higher PM2.5 and PM10 was associated with 4.9 pg/ml (95% CI: 1, 8.7) and 3.7 pg/ml (95% CI: 1.3, 6.1) higher Aβ 1-40 level respectively. A 6 ppb higher NO2 was associated with 3.5 pg/ml (95%CI: -0.09, 7.2) higher Aβ 1-40. An IQR higher PM10 was associated with 0.004 pg/ml lower ratio of Aβ 1-42/Aβ 1-40 (95% CI: -0.007, -0.0006). We will also present repeat measures results. Conclusions: Preliminary findings suggest an association between PM2.5, PM10 and NO2 and the protein Aβ 1-40. Additional toxicological and epidemiologic research can corroborate this novel association.