Iron deficiency is a common problem in family practice and can occur throughout a person’s lifespan. The reasons are varied, as are the symptoms that a deficient iron level can cause. At the 13th Iron Academy, renowned experts explained which patients merit a closer look, what challenges exist in diagnostics, and how iron can be effectively substituted.
Iron is essential for a number of other metabolic processes such as oxidation protection, cellular respiration, citric acid cycle, energy and purine metabolism, in addition to its well-known function as oxygen transport. Two-thirds of the trace element is present as functional iron, primarily in hemoglobin, while the remaining third is available to erythropoiesis as a storage form. Dietary iron can be absorbed directly by enterocytes in the duodenum if it is present as divalent iron. Trivalent iron is reduced to divalent by ferrin reductase. One of the most important regulators of iron absorption is the hormone hepcidin, which decreases iron release from enterocytes and macrophages by inhibiting ferroportin.
Iron deficiency can present in different forms, as Prof. A. von Eckardstein, MD, explained (Fig. 1) . According to guidelines, a test combination of hemoglobin, ferritin, transferrin saturation and CRP should be selected for effective diagnosis.
Iron deficiency can occur at any age
Worldwide, more than two billion people – children and adults alike – live with iron levels that are too low. There is a risk especially in premature infants, preschool children with excessive consumption of cow’s milk or vegetarian diet, female adolescents with heavy menstruation, pregnant women and elderly patients due to malnutrition. Chronic fatigue, general weakness, loss of appetite, increased hair loss or sleep disturbances can be signs of iron deficiency, among others.
Effects on heart health
Iron deficiency is also very common, especially in HFrEF patients, at 54% – predominantly in women and patients with anemia, high NT-proBNP, and/or elevated hsCRP. The effects can be far-reaching. PD Dr. med. M.T. Maeder used study results to show that the prognosis deteriorates significantly. Survival in patients without iron deficiency averaged 66.7% and 53.6% in those with additional iron deficiency. Iron deficiency was defined as ferritin <100 µg/l or ferritin 100-300 µg/l and TFS <20%. The higher the NYHA status, the greater the likelihood of iron deficiency and/or anemia.
Oral or IV iron substitution?
A number of both oral and intravenous iron administrations are available for substitution. Oral administration is still frequently used, although the onset of action is delayed compared to parenteral administration. In contrast, according to the current ESC guideline, patients with heart failure should be treated immediately with ferrocarboxymaltose. For example, in a clinical trial, a difference in 6-minute walking distance of 33 m was achieved compared with placebo.
Correction of iron deficiency with intravenous iron supplementation improves quality of life, increases exercise capacity, and reduces the risk of heart failure-related rehospitalization. According to the latest studies, oral iron therapy is not sufficiently effective.
Source: Iron Academy
HAUSARZT PRAXIS 2020; 15(12): 36 (published 10/12/20, ahead of print).
