Associations among Drinking Water Quality, Dyslipidemia, and Cognitive Function for OlderAdults in China

Abstract

AbstractBackgroundEpidemiological evidence has shown that poor drinking water quality can lead to dyslipidemia, which might be associated with cognitive decline or lower domain‐specific cognitive function in older adults. Given the prevalence of water pollution, dyslipidemia, and dementia in China, it is important to examine the association between drinking water quality and cognitive function in older Chinese and to identify the direct and indirect effects of drinking water quality and dyslipidemia on their cognitive function.MethodPrimary data for the study were selected from China Health and Retirement Longitudinal Study (CHARLS, 2015) and 4,951 respondents aged 60 and above were included. Data on drinking water quality were selected from the 2015 prefectural water quality data from the Institute of Public and Environment Affairs in China. Mixed effects models were conducted to assess the associations of cognitive function with drinking water quality and dyslipidemia. The mediation effects of dyslipidemia were examined by path analyses.ResultExposure to high quality drinking water was significantly associated with higher scores in mental status, episodic memory, and global cognition (β = 0.34, p < 0.001 for mental status; β = 0.24, p < 0.05 for episodic memory; β = 0.58, p < 0.01 for global cognition). Respondents who reported dyslipidemia diagnosis had higher scores in the three composite measures of cognitive function (β = 0.39, p < 0.001 for mental status; β = 0.27 p < 0.05 for episodic memory; β = 0.66, p < 0.001 for global cognition). An elevated blood triglycerides was only associated with higher scores in mental status (β = 0.21, p < 0.05). Self‐reported dyslipidemia diagnosis was a suppressor, which increased the magnitude of the direct effect of drinking water quality on mental status, episodic memory, and global cognition.ConclusionDrinking water quality was associated with cognitive function in older Chinese and the relationship was independent of natural or socioeconomic variations in neighborhood environments. Improving drinking water quality could be a potential public health effort to delay the onset of cognitive impairment and prevent the dementia pandemic in older people.