Sex Specificity in the Mixed Effects of Blood Heavy Metals and Cognitive Function on Elderly: Evidence from NHANES

Abstract

The way that males and females react to environmental exposures and negative impacts on their neurological systems is often different. Although previous research has examined the cognitively impairing effects of solitary metal exposures, the relationship between metal mixtures and cognitive function, particularly when considering an individual’s sex, remains elusive. This study aimed to investigate the sex differences in the association between multiple metal combinations and cognitive function in older Americans. This research employed the 2011–2014 NHANES survey of elderly Americans. The association between five mixed metals and four cognitive tests (the animal fluency test (AFT), the digit symbol substitution test (DSST), the instant recall test (IRT), and the delayed recall test (DRT)) were investigated with generalized linear regression model (GLM), Bayesian kernel machine regression model (BKMR), weighted quantile sum regression model (WQS), and quantile g-computation regression model (Qgcomp). A total of 1833 people, including 883 males and 950 females, enrolled in this cross-sectional study. We discovered that blood lead and blood cadmium were negatively associated with cognitive performance, while blood selenium demonstrated a positive association with cognitive function in older people. The negative relationship of heavy metal combinations on cognitive function might be somewhat reduced or even reversed via selenium. The IRT, AFT, and DSST are three of the four cognitive tests where men had more dramatic positive or negative results. There was a sex-specific connection between blood metal ratios and cognitive function among older Americans, as evidenced by the more significant relationship between mixed metals and cognitive performance in men (either positively or negatively). These results emphasize the impacts of ambient heavy metal exposure on cognitive function by employing sex-specific methods.

Sex-specific associations of urinary mixed-metal concentrations with femoral bone mineral density among older people: an NHANES (2017–2020) analysis

“…Therefore, it is crucial to explore the effects of mixed exposure to multiple metals on BMD. Noticeably, sex-specific associations of heavy metals with liver fibrosis, kidney function and cognitive function were observed in previous studies (18)(19)(20).…”

Environment-Wide Association Study of Cognitive Function in U.S. Older Adults using the NHANES Data

“…Previous studies have shown that exposure to Cd can impair cognitive performance both in isolated exposure scenarios and in combination with other environmental chemicals identified through EWAS screening. [24][25][26][27] It is also well known that Cd causes vascular damage and promotes atherosclerosis 88 by generating reactive oxygen species, disrupting sulfhydryl homeostasis, and downregulating nitric oxide. 89 Stroke affects cognitive domains such as attention, memory, and language.…”

“…17,21 Several studies have assessed associations between exposures to environmental chemicals and cognitive decline in specific populations. For example, exposures to metals, typically manganese (Mn), 22-24 cadmium (Cd), [24][25][26][27] lead (Pb), [25][26][27] barium (Ba), 24 cobalt (Co), 24 cesium (Cs), 24 and thallium (TI) 24 were reported to increase the risk of low cognitive performance. In addition, higher urinary 3-phenoxybenzoic acid concentrations in adults were associated with cognitive dysfunction 28 and it was observed that butyl benzyl phthalate is a potential cognitive-disrupting compound.…”

Assessing the Health Risk and Trophic Transfer of Lead and Cadmium in Dairy Farming Systems in the Mantaro Catchment, Central Andes of Peru

“…Scientific information indicates that elevated Pb and Cd concentrations impair neurological development and function in human populations. Simultaneous ingestion has several effects on the CNS, and in addition to causing cognitive impairment, it can impact social behavior and be responsible for increased depressive disorders [110][111][112][113], generalized anxiety disorders, panic/agoraphobia, and psychological conditions that could even lead to suicide [114][115][116][117]. Clinical research reports that patients with depressive disorders and panic attacks have high concentrations of Pb and Cd in their system [118].…”