{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T08:10:26Z","timestamp":1791360626775,"version":"4.3.1"},"reference-count":36,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T00:00:00Z","timestamp":1769990400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000272","name":"National Institute of Health Research","doi-asserted-by":"crossref","award":["17\/63\/131"],"award-info":[{"award-number":["17\/63\/131"]}],"id":[{"id":"10.13039\/501100000272","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100000272","name":"National Institute of Health Research","doi-asserted-by":"crossref","award":["17\/63\/131"],"award-info":[{"award-number":["17\/63\/131"]}],"id":[{"id":"10.13039\/501100000272","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>Results from a few studies have been conflicting regarding whether iron deficiency affects HbA1c reliability, and the mechanisms by which iron might influence HbA1c are not fully understood. We aimed to compare the relationship between HbA1c and average glucose levels measured by continuous glucose monitoring, retrospectively, in iron-replete and iron-deplete states among non-anemic type 2 diabetes mellitus (T2DM) patients.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We compared the differences in HbA1c between iron-replete and iron-deplete groups using the Chi-square test for categorical data and the Mann-Whitney U test for continuous data. We also evaluated the correlation between HbA1c and mean plasma glucose for both iron-replete and iron-deplete individuals using Pearson\u2019s correlation and linear regression.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>A total of 146 of the 213 participants screened had complete data and were included in the final analysis. 43 out of 146 (29.5%) had iron deficiency, and 103 were iron-replete. No significant difference was observed in HbA1c levels between iron-replete and iron-deplete individuals: 69 (51.0, 85.0) vs 62 (46.0, 83.0) mmol\/mol, P\u2009=\u20090.291). There was a strong positive correlation between HbA1c and mean plasma glucose concentration for both iron-replete and iron-deplete individuals (Pearson Correlation coefficient: 0.88 (0.83\u20130.92) and 0.93 (0.88\u20130.98), respectively).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec004\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>HbA1c correlates well with mean blood glucose even in the iron-deplete state amongst non-anaemic T2DM individuals. However, larger studies are needed to confirm these findings, particularly at screening and diagnostic thresholds.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pone.0323034","type":"journal-article","created":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T18:39:38Z","timestamp":1770057578000},"page":"e0323034","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":3,"title":["Comparative assessment of the impact of iron deficiency on HbA1c accuracy in non-anaemic individuals with type 2 diabetes: A secondary data analysis"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1925-4081","authenticated-orcid":true,"given":"Rogers John","family":"Mukasa","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nathan","family":"Mubiru","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7951-5458","authenticated-orcid":true,"given":"Isaac","family":"Sekitoleko","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ronald","family":"Makanga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hubert","family":"Nkabura","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Terry","family":"Ongaria","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Viola","family":"Mugamba","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wisdom","family":"Nakanga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Moffat J.","family":"Nyirenda","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0939-9380","authenticated-orcid":true,"given":"Anxious J.","family":"Niwaha","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,2,2]]},"reference":[{"key":"pone.0323034.ref001","doi-asserted-by":"crossref","first-page":"107840","DOI":"10.1016\/j.diabres.2019.107840","article-title":"IDF Diabetes Atlas: A review of studies utilising retinal photography on the global prevalence of diabetes related retinopathy between 2015 and 2018","volume":"157","author":"RL Thomas","year":"2019","journal-title":"Diabetes Res Clin Pract"},{"issue":"2","key":"pone.0323034.ref002","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1093\/trstmh\/try124","article-title":"The double burden of diabetes and global infection in low and middle-income countries","volume":"113","author":"S Dunachie","year":"2019","journal-title":"Trans R Soc Trop Med Hyg"},{"key":"pone.0323034.ref003","article-title":"Standards of medical care in diabetes\u20132006","volume":"29","year":"2006","journal-title":"Diabetes Care"},{"issue":"8","key":"pone.0323034.ref004","first-page":"616","article-title":"HbA1c and factors other than diabetes mellitus affecting it","volume":"51","author":"S Nitin","year":"2010","journal-title":"Singapore Med J"},{"issue":"1","key":"pone.0323034.ref005","doi-asserted-by":"crossref","first-page":"26","DOI":"10.4103\/2230-8210.196017","article-title":"Effects of thyroid status on glycated hemoglobin","volume":"21","author":"R Bhattacharjee","year":"2017","journal-title":"Indian J Endocrinol Metab"},{"issue":"4","key":"pone.0323034.ref006","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/j.blre.2017.02.004","article-title":"New insights into iron deficiency and iron deficiency anemia","volume":"31","author":"C Camaschella","year":"2017","journal-title":"Blood Rev"},{"issue":"8186","key":"pone.0323034.ref007","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/S0140-6736(80)90019-7","article-title":"Iron deficiency and glycosylated haemoglobin A","volume":"2","author":"AP Brooks","year":"1980","journal-title":"Lancet"},{"issue":"8193","key":"pone.0323034.ref008","doi-asserted-by":"crossref","first-page":"531","DOI":"10.1016\/S0140-6736(80)91853-X","article-title":"Glycosylated haemoglobin and iron deficiency","volume":"2","author":"WJ Sluiter","year":"1980","journal-title":"Lancet"},{"issue":"2","key":"pone.0323034.ref009","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/j.dsx.2013.02.004","article-title":"HbA1c and iron deficiency: a review","volume":"7","author":"J Ahmad","year":"2013","journal-title":"Diabetes Metab Syndr"},{"issue":"1","key":"pone.0323034.ref010","doi-asserted-by":"crossref","DOI":"10.1136\/bmjdrc-2021-002350","article-title":"HbA1c performs well in monitoring glucose control even in populations with high prevalence of medical conditions that may alter its reliability: the OPTIMAL observational multicenter study","volume":"9","author":"AJ Niwaha","year":"2021","journal-title":"BMJ Open Diabetes Res Care"},{"issue":"3","key":"pone.0323034.ref011","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1016\/j.diabres.2009.12.013","article-title":"Effect of age and race\/ethnicity on HbA1c levels in people without known diabetes mellitus: implications for the diagnosis of diabetes","volume":"87","author":"MB Davidson","year":"2010","journal-title":"Diabetes Res Clin Pract"},{"issue":"8","key":"pone.0323034.ref012","doi-asserted-by":"crossref","first-page":"927","DOI":"10.1111\/dme.12459","article-title":"Aging is associated with increased HbA1c levels, independently of glucose levels and insulin resistance, and also with decreased HbA1c diagnostic specificity","volume":"31","author":"N Dubowitz","year":"2014","journal-title":"Diabet Med"},{"issue":"2","key":"pone.0323034.ref013","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1111\/pedi.13297","article-title":"HbA1c percentiles and the association between BMI, age, gender, puberty, and HbA1c levels in healthy German children and adolescents","volume":"23","author":"I Hovestadt","year":"2022","journal-title":"Pediatr Diabetes"},{"key":"pone.0323034.ref014","doi-asserted-by":"crossref","first-page":"1098012","DOI":"10.3389\/fendo.2022.1098012","article-title":"Association of hemoglobin A1c with the incidence of hypertension: A large prospective study","volume":"13","author":"X Huang","year":"2023","journal-title":"Front Endocrinol (Lausanne)"},{"issue":"1","key":"pone.0323034.ref015","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1007\/BF02913083","article-title":"Effect of increasing duration of diabetes mellitus type 2 on glycated hemoglobin and insulin sensitivity","volume":"21","author":"M Verma","year":"2006","journal-title":"Indian J Clin Biochem"},{"key":"pone.0323034.ref016","doi-asserted-by":"crossref","unstructured":"Heyningen C v, Dalton R. Glycosylated haemoglobin in iron-deficiency anaemia. 1985.","DOI":"10.1016\/S0140-6736(85)92234-2"},{"issue":"1","key":"pone.0323034.ref017","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1111\/j.1753-0407.2010.00100.x","article-title":"Iron-deficiency anemia, non-iron-deficiency anemia and HbA1c among adults in the US","volume":"3","author":"ES Ford","year":"2011","journal-title":"J Diabetes"},{"key":"pone.0323034.ref018","unstructured":"Rai K, Pattabiraman T. Glycosylated haemoglobin levels in iron deficiency anaemia. 1986."},{"issue":"3","key":"pone.0323034.ref019","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/S0168-8227(00)00187-X","article-title":"Correlation among fasting plasma glucose, two-hour plasma glucose levels in OGTT and HbA1c","volume":"50","author":"C Ito","year":"2000","journal-title":"Diabetes Res Clin Pract"},{"issue":"5","key":"pone.0323034.ref020","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1373\/clinchem.2006.079756","article-title":"Variability in the relationship between mean plasma glucose and HbA1c: implications for the assessment of glycemic control","volume":"53","author":"ES Kilpatrick","year":"2007","journal-title":"Clin Chem"},{"issue":"2","key":"pone.0323034.ref021","first-page":"275","article-title":"Defining the relationship between plasma glucose and HbA(1c): analysis of glucose profiles and HbA(1c) in the diabetes control and complications trial","volume":"25","author":"CL Rohlfing","year":"2002","journal-title":"Diabetes Care"},{"issue":"2","key":"pone.0323034.ref022","doi-asserted-by":"crossref","first-page":"34","DOI":"10.3390\/jcm7020034","article-title":"Influence of Iron Deficiency on HbA1c levels in pregnant women: comparison with non-pregnant women","volume":"7","author":"K Hashimoto","year":"2018","journal-title":"J Clin Med"},{"issue":"6","key":"pone.0323034.ref023","doi-asserted-by":"crossref","DOI":"10.1038\/nutd.2015.16","article-title":"Implications of iron deficiency\/anemia on the classification of diabetes using HbA1c","volume":"5","author":"SM Attard","year":"2015","journal-title":"Nutr Diabetes"},{"issue":"2","key":"pone.0323034.ref024","first-page":"164","article-title":"Review on iron and its importance for human health","volume":"19","author":"N Abbaspour","year":"2014","journal-title":"J Res Med Sci"},{"issue":"23","key":"pone.0323034.ref025","doi-asserted-by":"crossref","first-page":"7287","DOI":"10.3390\/jcm12237287","article-title":"The effect of iron replacement therapy on HbA1c levels in diabetic and nondiabetic patients: a systematic review and meta-analysis","volume":"12","author":"AM AlQarni","year":"2023","journal-title":"J Clin Med"},{"issue":"10021","key":"pone.0323034.ref026","doi-asserted-by":"crossref","first-page":"907","DOI":"10.1016\/S0140-6736(15)60865-0","article-title":"Iron deficiency anaemia","volume":"387","author":"A Lopez","year":"2016","journal-title":"Lancet"},{"key":"pone.0323034.ref027","doi-asserted-by":"crossref","unstructured":"Camaschella C. Iron-deficiency anemia. new england journal of medicine. 2015;372(19):1832\u201343.","DOI":"10.1056\/NEJMra1401038"},{"key":"pone.0323034.ref028","doi-asserted-by":"crossref","DOI":"10.3945\/ajcn.117.155960","article-title":"Serum ferritin as an indicator of iron status: what do we need to know?","volume":"106","author":"J Daru","year":"2017","journal-title":"Am J Clin Nutr"},{"key":"pone.0323034.ref029","first-page":"9394060","article-title":"Limitations of serum ferritin in diagnosing iron deficiency in inflammatory conditions","volume":"2018","author":"A Dignass","year":"2018","journal-title":"Int J Chronic Dis"},{"issue":"4","key":"pone.0323034.ref030","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1016\/j.bpa.2023.11.001","article-title":"Diagnosing iron deficiency: Controversies and novel metrics","volume":"37","author":"JA Rusch","year":"2023","journal-title":"Best Pract Res Clin Anaesthesiol"},{"issue":"9","key":"pone.0323034.ref031","doi-asserted-by":"crossref","first-page":"1313","DOI":"10.2337\/diacare.16.9.1313","article-title":"The response of GHb to stepwise plasma glucose change over time in diabetic patients","volume":"16","author":"Y Tahara","year":"1993","journal-title":"Diabetes Care"},{"issue":"9","key":"pone.0323034.ref032","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pmed.1002383","article-title":"Impact of common genetic determinants of Hemoglobin A1c on type 2 diabetes risk and diagnosis in ancestrally diverse populations: A transethnic genome-wide meta-analysis","volume":"14","author":"E Wheeler","year":"2017","journal-title":"PLoS Med"},{"issue":"1","key":"pone.0323034.ref033","doi-asserted-by":"crossref","DOI":"10.31083\/j.ceog5101024","article-title":"Impact of Iron Deficiency Anemia on Hemoglobin A1c Levels in Diabetic and Non-Diabetic Pregnant Women","volume":"51","author":"A Firat","year":"2024","journal-title":"Clin Exp Obstet Gynecol"},{"key":"pone.0323034.ref034","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.clinbiochem.2015.09.004","article-title":"Effect of iron deficiency anaemia on HbA1c levels is dependent on the degree of anaemia","volume":"49","author":"JF Silva","year":"2016","journal-title":"Clin Biochem"},{"issue":"1","key":"pone.0323034.ref035","doi-asserted-by":"crossref","first-page":"17","DOI":"10.3343\/alm.2012.32.1.17","article-title":"Effect of iron deficiency anemia on hemoglobin A1c levels","volume":"32","author":"N Sinha","year":"2012","journal-title":"Ann Lab Med"},{"issue":"2","key":"pone.0323034.ref036","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1111\/j.1365-2796.1990.tb00131.x","article-title":"Glycosylated haemoglobin (HbA1c) in iron- and vitamin B12 deficiency","volume":"227","author":"P Gram-Hansen","year":"1990","journal-title":"J Intern Med"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0323034","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T18:39:44Z","timestamp":1770057584000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0323034"}},"subtitle":[],"editor":[{"given":"Samuel Kofi","family":"Tchum","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,2,2]]},"references-count":36,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,2,2]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0323034","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,2]]}}}