Associations Between PM Exposure and Alzheimer's Disease Prevalence Among Elderly in Eastern China

Background: Studies showed that PM might be associated with various neurogenic diseases such as Alzheimer's Disease (AD). However, this topic had been little studied in Zhejiang province of China.  METHODS: In 2018, we established a cohort of AD high-risk population with 1,742 elderly aged 60 and above. In 2020, the cohort was followed up, a total of 1,545 people participated the 2 surveys. Data collection included questionnaires and basic physical examinations. The average residential exposure to PM for each participant, that in a 5-years period prior to the first survey, was estimated using a satellite-based spatial statistical model. We determined the association between PM and AD prevalence by cox proportional hazards regression model.  RESULTS: This study showed that an increase in the PM level was an important associated risk factor that contributed to AD. The average PM exposure levels among the study population ranged from 32.69 μg/m to 39.67 μg/m from 2013 to 2017, which were much higher than 5 μg/m that specified in the WHO air quality guidelines. There was an association between PM exposure and AD, and the correlations between PM and Mini-Mental State Examination, Montreal cognitive assessment scale scores were statistically significant. An increase in the PM level by 10 μg/m elevated the risk of AD among residents by 2%-5% (HR  = 1.02 to 1.05, CI  = 1.01-1.10). The subgroups of male, with old age, with low education levels, used to work as farmers or blue-collar workers before retirement, overweight and obese were associated with a higher effect of PM.

Conclusions: Reducing PM exposure might be a good way to prevent AD.