Background and Objectives: Cadmium is a toxic heavy metal with a long biological half-life; exposure to it may impact cardiovascular health. Despite existing concerns, human evidence regarding the link between cadmium and blood pressure remains inconsistent. This narrative review aimed to summarize epidemiological evidence concerning the association of blood and urinary cadmium levels with blood pressure outcomes, while also examining potential mechanisms and methodological considerations.
Methods: Databases including PubMed, Scopus, Embase, and Google Scholar were searched up to March 2025. Observational studies investigating the association of blood or urinary cadmium with systolic blood pressure (SBP), diastolic blood pressure (DBP), or hypertension (HTN) were selected. Due to heterogeneity in the definitions of exposure and outcomes, a narrative synthesis was conducted rather than a meta-analysis.
Results: Overall, the evidence supports a positive association between cadmium exposure and elevated blood pressure, though results vary across studies and populations. In several large cross-sectional studies, blood cadmium was associated with higher SBP, DBP, and hypertension; conversely, urinary cadmium showed either positive or inverse associations, depending on the population studied and adjustments for renal function. This association appeared stronger in women, non-smokers, and individuals with impaired renal function. However, the strength of the association and the specific dose-response pattern remain unclear.
Conclusion: Cadmium exposure may be associated with elevated blood pressure; However, the predominance of cross-sectional studies, methodological heterogeneity, and residual confounding limit the interpretation of the results. Conducting prospective studies with standardized definitions of exposure and outcome is essential.