Cadmium exposure and incidence of heart failure and atrial fibrillation: a population-based prospective cohort study

Objectives: Cadmium is a non-essential toxic metal with multiple adverse health effects. Cadmium has been shown to be associated with cardiovascular diseases, but few studies have investigated heart failure (HF) and none of them reported atrial fibrillation (AF). We examined whether cadmium exposure is associated with incidence of HF or AF. Design: A prospective, observational cohort study with a 17-year follow-up. Setting: The city of Malmo, Sweden. Participants: Blood cadmium levels were measured in 4378 participants without a history of HF or AF (aged 46-67 years, 60% women), who participated in the Malmo Diet and Cancer (MDC) study during 1992-1994. Primary and secondary outcome measures: Incidence of HF and AF were identified from the Swedish hospital discharge register. Results: 143 participants (53% men) were diagnosed with new-onset HF and 385 individuals (52% men) were diagnosed with new-onset AF during follow-up for 17 years. Blood cadmium in the sex-specific 4th quartile of the distribution was significantly associated with incidence of HF. The (HR, 4th vs 1st quartile) was 2.64 (95% CI 1.60 to 4.36), adjusted for age, and 1.95 (1.02 to 3.71) after adjustment also for conventional risk factors and biomarkers. The blood cadmium level was not significantly associated with risk of incident AF. Conclusions: Blood cadmium levels in the 4th quartile were associated with increased incidence of HF in this cohort with comparatively low exposure to cadmium. Incidence of AF was not associated with cadmium.