JAMA Netw Open

High urinary metal levels linked to cognitive decline and dementia risk

December 5, 2024

Study design: This multicenter prospective cohort study analyzed data from the Multi-Ethnic Study of Atherosclerosis (MESA), which included 6,303 participants followed from 2000 to 2018. Urine samples collected at baseline were tested for arsenic, cadmium, cobalt, copper, lead, manganese, tungsten, uranium, and zinc levels. Cognitive tests (Digit Symbol Coding, Cognitive Abilities Screening Instrument, and Digit Span) were administered in 2010-2012, and dementia diagnoses were tracked through 2018.

Results: Higher urinary levels of arsenic, cadmium, cobalt, copper, tungsten, uranium, and zinc were associated with worse performance on cognitive tests and an increased risk of dementia. Specifically, the hazard ratios for dementia ranged from 1.15 for tungsten to 1.46 for uranium. The combined effect of the nine-metal mixture showed a significant increase in dementia risk, with a joint hazard ratio of 1.71 when comparing the 95th with the 25th percentile of metal levels.

Impact on clinical practice: The findings highlight the potential neurotoxic effects of chronic low-level metal exposure. Considering environmental and occupational histories may be beneficial when assessing cognitive decline and dementia risk.

Source:

Domingo-Relloso A, et al. (2024, December 2). JAMA Netw Open. Urinary Metal Levels, Cognitive Test Performance, and Dementia in the Multi-Ethnic Study of Atherosclerosis. https://pubmed.ncbi.nlm.nih.gov/39621345/