High Cadmium Level Associated With Cognitive Impairment Risk

TOPLINE:

High levels of urinary cadmium are associated with double the risk for global cognitive impairment in White adults, a new study shows. There was no such association between the heavy metal and cognitive function in Black adults.

METHODOLOGY:

• Investigators reviewed data on 2172 adults (mean age, 64 years; 61% White; 39% Black; 55% women) from the ongoing REGARDS population-based prospective cohort study in the United States who were free of cognitive impairment or stroke at baseline.
• Global cognitive impairment was assessed annually using the Six-Item Screener, and domain-based cognitive impairment was assessed every 2 years using the Enhanced Cognitive Battery.
• Blood and urine samples were collected from the participants at baseline, and levels of urinary cadmium were assessed using a urinary creatinine-correction method.
• Covariates included participants’ age, sex, smoking pack-years, alcohol consumption, and education level.
• Mean follow-up was 10 years.

TAKEAWAY:

• Global cognitive impairment was observed in 195 cases and domain-based cognitive impairment in 53 cases.
• High levels of urinary cadmium were associated with double the risk of developing global cognitive impairment in White adults (odds ratio [OR], 2.07; 95% CI, 1.18-3.64).
• No association was observed between urinary cadmium and global cognitive impairment in the overall cohort or in Black adults.
• Median smoking pack-years — a significant source of cadmium exposure for the US population — was significantly higher in White participants than Black participants (P = .001 for the highest tertile of urinary cadmium concentration).

IN PRACTICE:

“These results need to be confirmed with studies that measure cadmium levels over time, include more people and follow people over a longer time, but there are many reasons to reduce exposure to cadmium, whether it’s through implementing policies and regulations for air pollution and drinking water or people changing their behaviors by stopping smoking or being around cigarette smoke,” lead author Liping Lu, MD, PhD, MS, Columbia University, New York City, said in a press release.

SOURCE:

The study was published online on September 4, 2024, in Neurology.

LIMITATIONS:

Urinary cadmium levels were tested only at baseline, which may not have captured changes in exposure over time. A limited number of patients with cognitive impairment used the Enhanced Cognitive Battery. The study did not include occupational information, and the potential for residual confounding from smoking could not be completely excluded. The follow-up time may have been insufficient for observing a significant effect on cognition, and competing risks for mortality associated with cadmium exposure could also have affected the findings.

DISCLOSURES:

The study was co-funded by the National Institute of Neurological Disorders and Stroke and the National Institute on Aging of the National Institutes of Health (NIH). Several authors were partially supported by the NIH. Detailed disclosures are provided in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.