Cohort study finds no association between cadmium biomarkers and dementia incidence in older adults, suggesting environmental cadmium may not drive neurodegenerative risk.
Key Points
To evaluate the prospective associations between cadmium exposure biomarkers and the incidence of Alzheimer's disease and all-cause dementia in US adults.
Linked NHANES III (1988–1994, N=6,122) and continuous NHANES (1999–2016; urinary cadmium N=2,833, blood cadmium N=8,038) data with Medicare claims through 2018 to identify incident dementia cases.
Evaluated urinary and blood cadmium biomarkers using covariate-adjusted, survey-weighted Cox proportional hazard models over long-term follow-up.
In NHANES III over a mean 20.4-year follow-up (743 AD, 1,508 dementia cases), urinary cadmium was not associated with AD (HR: 1.01, 95% CI: 0.9–1.0) or all-cause dementia (HR: 1.02, 95% CI: 0.96–1.08).
In continuous NHANES over a mean 9.5-year follow-up (587 AD, 1,260 dementia cases), urinary cadmium showed no association with AD (HR: 1.09, 95% CI: 0.9–1.4) or dementia (HR: 1.07, 95% CI: 0.9–1.3).
Blood cadmium in continuous NHANES similarly showed no association with incident AD (HR: 1.06, 95% CI: 0.9–1.2) or all-cause dementia (HR: 1.06, 95% CI: 0.95–1.2).