Cadmium exposure and cancer mortality in the Third National Health and Nutrition Examination Survey cohort

Objective This study examined prospective data from the Third National Health and Nutrition Examination Survey (NHANES III) cohort to investigate the relationship between cadmium exposure and cancer mortality, and the specific cancers associated with cadmium exposure, in the general population. Methods Vital status and cause of death through 31 December 2006 were obtained by the National Center for Health Statistics for NHANES III participants. The cadmium concentration of spot urine samples was measured and corrected for urine creatinine (uCd). Weighted Cox proportional hazards regression with age as the time metric was applied to estimate sex-specific adjusted HRs (aHRs) of mortality associated with uCd for all cancers and the cancers responsible for the most deaths in the USA. Estimates were stratified by smoking history and adjusted for education, body mass index and race. Results uCd was associated with cancer mortality (aHR per twofold higher uCd (95% CI), men: 1.26 (1.07 to 1.48); women: 1.21 (1.04 to 1.42)). In men, mortality from lung cancer, pancreatic cancer and non-Hodgkin lymphoma was associated with uCd; an association with leukaemia mortality was suggested. In women, associations were suggested with mortality due to lung cancer, leukaemia, ovarian and uterine cancer, but evidence was weaker than in men. Conclusions Cadmium appears to be associated with overall cancer mortality in men and women, but the specific cancers associated differ between men and women, suggesting avenues for future research. Limitations of the study include the possibility of uncontrolled confounding by cigarette smoking or other factors, and the limited number of deaths due to some cancers.