Хелатотерапія

In chelation therapy, a biologically based practice, a drug is used to bind with and remove hypothesized excess or toxic amounts of a metal or mineral (eg, lead, copper, iron, calcium) from the bloodstream. In conventional medicine, chelation therapy is a widely accepted way to treat lead and other heavy metal poisoning (see table Guidelines for Chelation Therapy). (See also Overview of Integrative, Complementary, and Alternative Medicine.)

Heavy metal toxicity, usually due to environmental exposure, may be a risk factor for dementia (1), cardiovascular disease (2), and chronic kidney disease (3).

Chelation therapy with EDTA (ethylene diamine tetraacetic acid) has also been suggested as a way to remove calcium and thus treat atherosclerosis. However, despite > 50 years of study, researchers have not identified any mechanism to explain how chelation therapy could treat atherosclerosis or prevent heart attacks or strokes (4).

In 2012, a large randomized, placebo-controlled trial of chelation (the Trial to Assess Chelation Therapy [TACT]) found a significant benefit for chelation over placebo for composite outcomes (26.5% versus 30% for placebo), but not for individual outcomes (eg, death, cardiovascular events, stroke, hospitalizations) (5). This study had methodological flaws and did not end the controversy over chelation therapy; however, a post-hoc review of the data showed a significant reduction in the composite endpoint in patients with diabetes and peripheral artery disease in the chelation group compared to the control group, as well as a reduction in mortality (6).

A subsequent systematic review of 38 studies showed possible but unclear benefits of chelation in regard to secondary prevention of recurrent cardiac events (7).

Risks of chelation therapy include

• Hypocalcemia (which is potentially serious)

• Infusion site reaction, fever, nausea, vomiting

• Kidney damage

• Delay of more effective treatment

• Death