Hongyu Li, et al. - Researchers performed a cross-sectional study to ascertain the association between cognitive function and blood cadmium levels in US adults aged 60 years or older. Findings revealed worse cognitive function in association with increased blood cadmium among these adults.

Methods

• Participants comprised of a total of 2,068 adults aged 60 years or older who completed four cognitive assessment tests and blood cadmium detection in two waves of National Health and Nutrition Examination Survey (NHANES) (2011–2014).
• Researchers conducted cognitive assessment by household interview or at a Mobile Examination Center (MEC) using the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Word List Learning Test, the CERAD Word List Recall Test, the Animal Fluency Test and the Digit Symbol Substitution Test (DSST).
• A composite cognitive z-score was created to represent global cognitive function.

Results

• The study participants showed the median blood cadmium concentration of 0.35μg/L, and the IQR of 0.24-0.56 μg/L.
• In linear regression analyses, blood cadmium as a continuous variable was observed to be inversely associated with the composite z-score (μg/L, β=-0.11, 95% CI -0.20 to -0.03) adjusting for demographics, behaviour and medical history.
• Similarly, researchers noted a relevant association between quartiles of blood cadmium and composite z-score, with somewhat lower scores in the upper quartile of exposure (blood cadmium ≥0.63μg/L) compared with those in the lower quartile of exposure (blood cadmium <0.25&mug/L) (μg/L, β=-0.14, 95% CI -0.25 to -0.03), and there was a trend by quartiles of blood cadmium (P<0.0001).