Israel Medical Association Journal

Background: Iron deficiency and lead poisoning are common and are often associated. This association has been suggested previously, mainly by retrospective cross-sectional studies.

Objective: To assess the impact of short-term lead exposure at indoor firing ranges, and its relationship to iron, ferritin, lead, zinc protoporphyrin, and hemoglobin concentrations in young adults.

Methods: We conducted a clinical study in 30 young healthy soldiers serving in the Israel Defense Forces. Blood samples were drawn for lead, zinc protoporphyrin, iron, hemoglobin and ferritin prior to and after a 6 week period of intensive target practice in indoor firing ranges.

Results: After a 6 week period of exposure to lead dust, a mean blood lead level increase (P < 0.0001) and a mean iron (P < 0.0005) and mean ferritin (P < 0.0625) decrease occurred simultaneously. We found a trend for inverse correlation between pre-exposure low ferritin levels and post-exposure high blood lead levels.

Conclusions: The decrease in iron and ferritin levels after short-term lead exposure can be attributed to competition between iron and lead absorption via divalent metal transport 1, suggesting that lead poisoning can cause iron depletion and that iron depletion can aggravate lead poisoning. This synergistic effect should come readily to every physician's mind when treating patients with a potential risk for each problem separately.
 

Systemic infection or inflammation causes a decrease in intestinal iron absorption and impairs the release of recycled iron from macrophages. Decreased availability of iron may deny this essential element to invading pathogens and may inhibit their multiplication and other metabolic processes but also results in anemia of chronic disease. This article reviews recent discoveries that shed light on the regulation of iron metabolism during infection and iron overload, and point to the central role of a newly discovered peptide, hepcidin. Evidence to date indicates that hepcidin is a negative regulator of intestinal iron absorption, placental iron transport, and the release of iron from macrophages that recycle iron from senescent red cells. It may also be the central mediator of iron sequestration during infections and inflammatory states and the mediator of anemia of chronic disease. Rapid progress in this area is a good example of the beneficial effects of improvements in peptide analysis and chemistry, advances in genomics, and the increasing use of transgenic mice to determine the function of newly discovered genes and proteins.