The role of iron deficiency (ID) in and beyond anaemia
Iron is essential for tissues with high mitogenic potential, such as haematopoietic cells, and/or high energy demand, such as renal cells and cardiomyocytes (summarised by Jankowska et al, 20101).
Chronic inflammatory conditions such as CHF and CKD perturb the recycling process of iron from senescent red blood cells and trap iron in the reticuloendothelial system leading to ID.2
There are a number of consequences of ID that are related not only to impaired erythropoiesis but also to impaired oxidative metabolism.4
- ID with and without anaemia is accompanied by reduced aerobic capacity,4 and its correction improves symptomatic performance and exercise tolerance in patients with CHF.5
ID is also associated with increased mortality in CHF patients (adjusted hazard ratio 1.58, 95% CI 1.14–2.17, P < 0.01.).1
ID appears to be underestimated in CHF patients.
- In a study of anaemic patients with CHF, examination of bone marrow biopsies revealed that 73% of patients had ID even though the mean ferritin level (113 ng/mL) was within the normal range.3
Given the association between ID and mortality, patients with CHF merit regular testing for ID.
References
1. Jankowska et al. Eur Heart J. 2010;31: 1872–80.
2. Wessling-Resnick M. Annu Rev Nutr 2010;30:105–102
3. Nanas JN et al. J Am Coll Cardiol 2006;48:2485–2489
4. Haas JD, Brownlie T. J Nutr. 2001 Feb;131(2S-2):676S-688S.
5. Anker SD et al. N Engl J Med 2009;361:2436–2448
