Estimating the burden of iron deficiency among African children

• Type of Material: Article
• Authors: John Muthil Muriuki, Kenya Medical Research Institute; Alexander J. Mentzer, University of Oxford; Emily L. Webb, London School of Hygiene & Tropical Medicine; Alireza Morovat, Oxford University Hospitals; Wandia Kimita, Kenya Medical Research Institute; Francis M. Ndungu, Kenya Medical Research Institute; Alex W. Macharia, Kenya Medical Research Institute; Rosie J. Crane, Kenya Medical Research Institute; James A. Berkley, Kenya Medical Research Institute; Swaib A. Lule, London School of Hygiene & Tropical Medicine; Clare Cutland, University of Witwatersrand; Sodiomon B. Sirima, Groupe de Recherche Action en Sante; Amidou Diarra, Groupe de Recherche Action en Sante; Alfred B. Tiono, Groupe de Recherche Action en Sante; Philip Bejon, Kenya Medical Research Institute; Shabir A. Madhi, University of Witwatersrand; Adrian V. S. Hill, University of Oxford; Andrew M. Prentice, London School of Hygiene & Tropical Medicine; Parminder Suchdev, Emory University; Alison M. Elliott, Uganda Virus Research Institute; Thomas N. Williams, Kenya Medical Research Institute; Sarah H. Atkinson, Kenya Medical Research Institute
• Language: English
• Date: 2020-02-27
• Publisher: BMC
• Publication Version: Final Published Version
• Copyright Statement: © 2020 The Author(s).
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1186/s12916-020-1502-7
• Title of Journal or Parent Work: BMC MEDICINE
• Volume: 18
• Issue: 1
• Start Page: 31
• End Page: 31
• Grant/Funding Information: This work was funded by Wellcome (Grant numbers [110255/Z/15/Z to SHA], [202800/Z/16/Z to TNW; 106289/Z/14/Z to AJM; and 064693, 079110, 095778 to AME] and with core awards to the KEMRI-Wellcome Trust Research Programme (203077/Z/16/Z). AJM was also supported by an Oxford University Clinical Academic School Transitional Fellowship and the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. PSS received funding from the US Centers for Disease Control & Prevention and the Bill and Melinda Gates Foundation (OPP1193736). JMM was funded through the DELTAS Africa Initiative (DEL-15-003). The DELTAS Africa Initiative is an independent funding scheme of the African Academy of Sciences (AAS)’s Alliance for Accelerating Excellence in Science in Africa (AESA) and supported by the New Partnership for Africa’s Development Planning and Coordinating Agency (NEPAD Agency) with funding from the Wellcome Trust [203077/Z/16/Z] and the UK government. The Gambian studies were supported by National Institute of Child Health and Development, Bill and Melinda Gates Foundation, core funding MC-A760-5QX00 to the MRC Unit The Gambia/MRC International Nutrition Group by the UK MRC and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement. This project also received funding from the European Research Council (ERC) under the European Union’s (Seventh Framework Programme [FP7/2007-2013]) (Grant agreement No 294557 to AVSH).
• Keywords: Science & Technology; ANEMIA; General & Internal Medicine; INFECTION; Iron deficiency; SOLUBLE TRANSFERRIN RECEPTOR; SERUM FERRITIN; PLASMODIUM-FALCIPARUM; Ferritin; IMMUNIZATION; Inflammation; Transferrin saturation; ACUTE-PHASE RESPONSE; Life Sciences & Biomedicine; MALARIA; Malaria; NUTRITIONAL DETERMINANTS; BIOMARKERS REFLECTING INFLAMMATION; African children; Medicine, General & Internal
• Research Categories: Health Sciences, Nutrition; Health Sciences, Public Health

Abstract

Background: Iron deficiency (ID) is a major public health burden in African children and accurate prevalence estimates are important for effective nutritional interventions. However, ID may be incorrectly estimated in Africa because most measures of iron status are altered by inflammation and infections such as malaria. Through the current study, we have assessed different approaches to the prediction of iron status and estimated the burden of ID in African children. Methods: We assayed iron and inflammatory biomarkers in 4853 children aged 0-8 years from Kenya, Uganda, Burkina Faso, South Africa, and The Gambia. We described iron status and its relationship with age, sex, inflammation, and malaria parasitemia. We defined ID using the WHO guideline (ferritin < 12 μg/L or < 30 μg/L in the presence of inflammation in children < 5 years old or < 15 μg/L in children ≥ 5 years old). We compared this with a recently proposed gold standard, which uses regression-correction for ferritin levels based on the relationship between ferritin levels, inflammatory markers, and malaria. We further investigated the utility of other iron biomarkers in predicting ID using the inflammation and malaria regression-corrected estimate as a gold standard. Results: The prevalence of ID was highest at 1 year of age and in male infants. Inflammation and malaria parasitemia were associated with all iron biomarkers, although transferrin saturation was least affected. Overall prevalence of WHO-defined ID was 34% compared to 52% using the inflammation and malaria regression-corrected estimate. This unidentified burden of ID increased with age and was highest in countries with high prevalence of inflammation and malaria, where up to a quarter of iron-deficient children were misclassified as iron replete. Transferrin saturation < 11% most closely predicted the prevalence of ID according to the regression-correction gold standard. Conclusions: The prevalence of ID is underestimated in African children when defined using the WHO guidelines, especially in malaria-endemic populations, and the use of transferrin saturation may provide a more accurate approach. Further research is needed to identify the most accurate measures for determining the prevalence of ID in sub-Saharan Africa.