Iron Status and Associated Malaria Risk Among African Children

• Published in: Clinical infectious diseases Vol. 68; no. 11; pp. 1807 - 1814
• Main Authors: Muriuki, John Muthii, Mentzer, Alexander J, Kimita, Wandia, Ndungu, Francis M, Macharia, Alex W, Webb, Emily L, Lule, Swaib A, Morovat, Alireza, Hill, Adrian V S, Bejon, Philip, Elliott, Alison M, Williams, Thomas N, Atkinson, Sarah H
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 17.05.2019
• Subjects: and Commentaries; Child; Child, Preschool; Epidemiological Monitoring; Female; Humans; Infant; Infant, Newborn; Iron - blood; Kenya - epidemiology; Longitudinal Studies; Malaria - epidemiology; Male; Medicin och hälsovetenskap; Nutritional Status; Prevalence; Prospective Studies; Randomized Controlled Trials as Topic; Retrospective Studies; Risk Factors; Trace Elements - blood; Uganda - epidemiology; Kenya; Uganda; malaria risk; African children; iron deficiency; iron status
• ISSN: 1058-4838; 1537-6591; 1537-6591
• DOI: 10.1093/cid/ciy791

Abstract Background It remains unclear whether improving iron status increases malaria risk, and few studies have looked at the effect of host iron status on subsequent malaria infection. We therefore aimed to determine whether a child’s iron status influences their subsequent risk of malaria infection in sub-Saharan Africa. Methods We assayed iron and inflammatory biomarkers from community-based cohorts of 1309 Kenyan and 1374 Ugandan children aged 0–7 years and conducted prospective surveillance for episodes of malaria. Poisson regression models were fitted to determine the effect of iron status on the incidence rate ratio (IRR) of malaria using longitudinal data covering a period of 6 months. Models were adjusted for age, sex, parasitemia, inflammation, and study site. Results At baseline, the prevalence of iron deficiency (ID) was 36.9% and 34.6% in Kenyan and Ugandan children, respectively. ID anemia (IDA) affected 23.6% of Kenyan and 17.6% of Ugandan children. Malaria risk was lower in children with ID (IRR, 0.7; 95% confidence interval [CI], 0.6, 0.8; P < .001) and IDA (IRR, 0.7; 95% CI, 0.6, 0.9; P = .006). Low transferrin saturation (<10%) was similarly associated with lower malaria risk (IRR, 0.8; 95% CI, 0.6, 0.9; P = .016). However, variation in hepcidin, soluble transferrin receptors (sTfR), and hemoglobin/anemia was not associated with altered malaria risk. Conclusions ID appears to protect against malaria infection in African children when defined using ferritin and transferrin saturation, but not when defined by hepcidin, sTfR, or hemoglobin. Additional research is required to determine causality. Clinical Trials Registration ISRCTN32849447 Decreased ferritin and transferrin saturation are associated with protection against malaria in African children. Hepcidin, soluble transferrin receptor, and hemoglobin concentrations are not associated with malaria protection. These findings may reflect differences in parasite iron acquisition.