Peters et al. 2021 — Cadmium and lead exposures and red cell distribution width in NHANES 2003-2016
This large cross-sectional study pooled NHANES (National Health and Nutrition Examination Survey) data from 2003 to 2016 to examine associations between blood cadmium (Cd) and blood lead (Pb) and red cell distribution width (RDW), a marker of erythrocyte size variability linked to inflammation and hematological dysfunction. The analysis included 24,607 participants representing the US general population. This study provides nationally representative blood cadmium and lead concentration data for US adults across a 13-year surveillance window, offering insight into population-level exposure distributions and demographic patterns. Blood Cd and Pb were measured by ICP-MS as part of the NHANES heavy metals component. The documented association between these blood metal levels and RDW suggests a mechanism linking dietary metal exposure to anemia-related and inflammatory hematological outcomes.
Key numbers
n=24,607 US adults (NHANES 2003-2016 pooled). Biomarker: blood cadmium and blood lead (ICP-MS). Outcome: red cell distribution width (RDW). Study design: pooled cross-sectional analysis of NHANES 6 survey cycles. Nationally representative US sample. Publication: PLoS ONE 2021 Jan;16(1):e0245173. License: CC BY.
Methods (brief)
Pooled analysis of NHANES 2003-2004 through 2015-2016 cycles. Blood Cd and Pb measured by ICP-MS at CDC clinical laboratory. Complex survey design accounted for in all analyses (sampling weights, strata, PSUs). Multivariable linear regression and quantile regression models adjusting for demographics, smoking, BMI. Limitation: cross-sectional design precludes causal inference; blood metals reflect recent exposure, not long-term body burden.
Implications
Certification: Provides US national population reference distributions for blood Cd and Pb; useful context for interpreting product concentration data and dietary exposure scenarios. Courses: Illustrates hematological health endpoints associated with cadmium and lead exposure in the general US population. App: NHANES blood metal data confirm that dietary Cd and Pb exposure is measurable and varies by demographic subgroup in the US general population.