Aging
Cadmium Exposure and Incidence of All-Cause Dementia and Alzheimer’s Disease in US Adults Erika Walker* Erika Walker Walker Walker Walker Walker Walker Walker Walker Walker Walker Walker School of Public Health, University of Michigan
Introduction: Longitudinal population studies aid in understanding risk factors for long-latency disorders like Alzheimer’s disease (AD) and all-cause dementia. Environmental exposures with neurotoxic effects, such as non-essential metals, may be modifiable risk factors for these conditions. We evaluated the association between cadmium exposure and AD/all-cause dementia incidence in US adults.
Methods: National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and continuous NHANES (1999-2016) data were linked with Medicare claims to identify incident AD and dementia cases through 2018. Urinary and/or blood cadmium were measured during NHANES. We used covariate-adjusted, survey-weighted Cox proportional hazard models to evaluate the associations between cadmium exposure biomarkers and AD/dementia over follow-up.
Results: In NHANES III (N=6,122), baseline age was 53.9±0.5 years and urinary cadmium was 0.8±0.02 ug/L. Over a follow-up of 20.4±0.3 years, 743 AD and 1,508 all-cause dementia cases occurred. Urinary cadmium was not associated with AD (HR: 1.01, 95% CI: 0.9-1.0) nor all-cause dementia incidence (HR: 1.02, 95% CI: 0.96-1.08). In continuous NHANES (urinary cadmium N=2,833; blood cadmium N=8,038), baseline age was 64.1±0.2 years, urinary cadmium was 0.5±0.03 ug/L, and blood cadmium was 0.6±0.01 ug/L. Over 9.5±0.1 years, 587 AD and 1,260 all-cause dementia cases occurred. Urinary and blood cadmium showed no associations with AD (HR [95% CI]: 1.09 [0.9, 1.4]; 1.06 [0.9, 1.2]) nor all-cause dementia (HR [95% CI]: 1.07 [0.9, 1.3]; 1.06 [0.95, 1.2]).
Conclusion: No associations between cadmium exposure and AD/dementia incidence were observed. Our null findings should be interpreted while considering potential methodological issues and verified by subsequent studies.