Title : Treatment of iron-deficiency anemia reduces pneumonia- and bacteremia-associated hospitalizations
Abstract:
Intro: The safety profile of oral iron supplementation is well established and generally benign, but many practitioners limit iron supplementation in patients hospitalized for infectious causes, even in the presence of iron-deficiency anemia (IDA). Nearly all human pathogens require iron, and must obtain it from the host, so administering iron during an infection is feared to exacerbate the infection. However, IDA itself is associated with worse outcomes in many infections, so iron stores must be balanced for optimal outcomes.
Objective: In this study, we examine the relationship between IDA, iron supplementation, and infection in hospitalized patients.
Methods: Inpatient admission data for pediatric patients from multiple institutions, from 2020 to 2023 were retrospectively analyzed for infectious diagnoses on or during admission, IDA (defined by the intersection of abnormal HgB, abnormal MCV, and abnormal RDW) and prescribed iron supplements. Of 91,029 total hospital admissions, 7344 patients had IDA, of whom 1994 were prescribed iron. 3249 patients were prescribed iron with no IDA by these criteria. Chi-squared analysis was performed on infection category: bacteremia, urinary tract infection (UTI), pneumonia, and meningitis, to find a correlation between IDA and infection, or iron supplementation and proportion of hospitalized patients with each infection.
Results: IDA correlated significantly with all infections analyzed. Iron supplementation in patients with no IDA correlated with increased likelihood of bacteremia and meningitis, but not UTI, and correlated inversely with pneumonia. In patients with IDA, iron supplementation correlated with decreased likelihood of pneumonia and bacteremia, but had no effect on meningitis or UTI.
Discussion/Conclusion: Our data describe the effects of anemia and iron in various infections. IDA correlates with an increased likelihood of all infections analyzed, on or during hospitalization, and iron supplementation increases proportions of certain infections only in patients without IDA. For patients with IDA, iron supplementation appears to be, at worst, benign in terms of risk of infection. However, iron supplementation actually decreases pneumonia at or during admission, regardless of IDA status. The lung is a unique immune organ, in which alveolar macrophages play a key role in homeostasis and infection control, and these macrophages require iron for multiple antimicrobial pathways. Thus, based on these data, and supported by an understanding of lung immunity, providing iron to iron-deficient patients is critical to support immune function, particularly to combat pneumonia.
