Exposure to heavy metals is common. This exposure is related to environmental contamination of air, water and soil, occupational exposure, accumulation in food, tobacco and other factors. Cadmium and lead are notable for their widespread contamination, long lasting effects in the body, and renal as well as cardiovascular toxicity. Acute toxicity due to high level exposure, as well as chronic low level exposure are now well-established pathogenic entities.
Both chronic renal failure and ischemic heart disease patients have been treated separately in recent studies with ethylenediaminetetraacetic acid (EDTA) chelation therapy. In patients with chronic kidney disease, serum creatinine 1.5-4.0 mg/dL, and increased body lead burden, weekly low dose chelation with calcium EDTA slowed the rate of decline in renal function in diabetics and non-diabetics. In patients with a history of myocardial infarction, the Trial to Assess Chelation Therapy study showed that EDTA chelation decreased the likelihood of cardiovascular events, particularly in diabetics. However, heavy metal levels were not measured in this study. It is clear that more research is needed in this area. There is also a need to more frequently consider and test for the possibility of cadmium and lead toxicity in patients with increased risk, such as those with hypertension, diabetes mellitus and chronic renal disease.