Neurology
Associations between plasma metal and metalloid levels and Alzheimer’s disease and related dementias among a cognitively healthy population-based cohort Terry Zhou* Terry Zhou Zhou Zhou Zhou Zhou Zhou Zhou Zhou Zhou Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
Introduction
Exposure to metals and metalloids has been linked to Alzheimer’s disease and related dementias (ADRD) pathology. However, research has been limited on the joint effects of multiple metal(loid) exposures on ADRD in human populations.
Methods
We estimated associations in 232 participants from the Emory Healthy Brain Study (EHBS) cohort. Concentrations of 13 metal(loid)s including beryllium (Be), vanadium (V), manganese (Mn), cobalt (Co), nickel (Ni), arsenic (As), cadmium (Cd), tin (Sn), antimony (Sb), tellurium (Te), cesium (Cs), barium (Ba), and uranium (U) were measured in plasma using inductively coupled plasma-mass spectrometry. ADRD was evaluated using the Mini Mental State Examination (MMSE). Associations between individual metal(loid) levels and MMSE were estimated using linear regression models, adjusting for potential confounding variables. Metal levels were dichotomized as detected/ not detected based on their limits of detection (LOD) due to high proportions of samples below the LOD. We applied quantile g-computation (qgcomp), using continuous exposure variables and adjusting for potential confounders, to estimate the joint effect of the total plasma metal mixture concentrations.
Results
Although detectable levels of Co, Cd, V, and Sb were associated with decreased MMSE scores (e.g., for Cd β=-0.26 (95% CI: -0.89, 0.38)), none of the associations was statistically significant. A statistically significant negative association was observed between the overall metal mixture concentration and MMSE (increasing all metal(loid) levels by one quantile β=-0.14 [-0.27, -0.01] (qgcomp)).
Discussion
While we found no significant associations between individual plasma metal(loid) levels and ADRD, the overall metal(loid) mixture concentration was significantly negatively associated with ADRD. Future research should further investigate the potential neurotoxic effects of these metal exposures to better target ADRD prevention measures.