Abstract 4357481: Modification of the Association of Functional Limitation and cardiovascular diseases by Toxic Metals exposure among US Adults

Background: Functional limitations are common among U.S. adults and are established predictors of cardiovascular disease (CVD). However, it is unclear whether exposure to toxic metals modifies the association between functional limitation and CVD risk. Methods: We analyzed data on 6,337 U.S. adults (≥18 years) from the National Health and Nutrition Examination Survey 2021–2023. Functional status was assessed in three domains: cognition, mobility, and seeing. Toxic metal exposures (blood lead, cadmium, mercury, manganese, selenium) were measured as "high" (≥90th percentile) vs "low." The outcome was CVD, defined as any history of heart failure, coronary heart disease, angina, myocardial infarction, or stroke. Survey-weighted descriptive statistics, cross-tabulations, and survey-weighted, multiple-imputed logistic regression models (adjusted for age, sex, race, education, income, BMI, diet, physical activity, sedentary time, alcohol, and smoking) were used to estimate main and interaction effects. Results: Functional limitations were prevalent: cognitive—47.8%, mobility—32.8%, and seeing—40.3%. CVD prevalence was 12.8%. Each metal was "high" in ~10% of participants in the study population. Across all domains and metals, CVD rates were lowest among those with no functional limitation and low metal exposure (cognition × lead: 8.6%) and highest among those with both limitation and high metal (cognition × high lead: 23.8%; mobility × high lead: 32.8%; seeing × high lead: 26.3%). In multivariable regression, any difficulty in cognition was 1.52 times (aOR for CVD: 1.52, 95% CI: 1.28–1.80), mobility 2.22 times (aOR 2.22, 1.09–4.09), and seeing 1.59 times (aOR 1.59, 1.07–2.44) were independently associated with higher CVD risk, regardless of toxic metal exposure. No significant interaction was observed between high metal exposure and functional limitation. Conclusions: Functional limitation in cognition, mobility, and seeing is a strong, independent predictor of CVD in U.S. adults. Although CVD prevalence was highest among those with high toxic metals exposure and functional limitation, toxic metals exposure did not significantly modify the strength of this association in multivariable analysis in the study population.