{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T18:38:40Z","timestamp":1775068720102,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2021,10,26]],"date-time":"2021-10-26T00:00:00Z","timestamp":1635206400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Jie Chan Chen Foundation","award":["unrestricted research grant"],"award-info":[{"award-number":["unrestricted research grant"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Hemoglobin A1C (A1C) is used in various settings. Its performance has not been evaluated systemically. We compared A1C in diagnosis of diabetes with fasting plasma glucose (FPG) and 2-h postchallenged plasma glucose (2hPG) parameters in a cross-sectional cohort in the United Stated. Adult subjects (\u226520 years) were identified from the National Health and Nutrition Examination Survey 2005\u20132016 without a history of diabetes who had BMI, A1C, FPG, and 2hPG (n = 10,416). For comparisons, we calculated the sample weighted prevalence, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with subgroup analyses. For the retinopathy study, diabetic subjects with established diabetes who responded to the question of diabetic retinopathy were evaluated (n = 3907). Compared to the FPG\/2hPG criteria, A1C \u2265 48 mmol\/mol (6.5%) had a low sensitivity at 25.90%, with specificity 99.70%, PPV 84.70%, and NPV 95.70%. Subgroup analyses revealed a lower sensitivity in males (24.52%); the lowest in non-Hispanic White (21.35%), in the third decade (14.32%), and in the BMI &lt; 22.50 kg\/m2 group (7.21%). The prevalence of self-reported diabetic retinopathy increased drastically with an inflection point at A1C 48 mmol\/mol (6.5%) from 11.52% to 18.32% (p &lt; 0.0001). A1C \u2265 48 mmol\/mol (6.5%) should be cautiously used to diagnose diabetes in certain subgroups due to very low sensitivity in certain groups. With the confirmation of the association of increasing self-reported diabetic retinopathy with A1C \u2265 48 mmol\/mol (6.5%), the current A1C cutoff is an acceptable value with the understanding of especially low sensitivity in certain subgroups.<\/jats:p>","DOI":"10.3390\/jcm10214947","type":"journal-article","created":{"date-parts":[[2021,10,26]],"date-time":"2021-10-26T23:54:33Z","timestamp":1635292473000},"page":"4947","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["The Role of Hemoglobin A1C in Diabetes Screening and Diabetic Retinopathy"],"prefix":"10.3390","volume":"10","author":[{"given":"Maria Mercedes","family":"Chang Villacreses","sequence":"first","affiliation":[{"name":"Department of Clinical Diabetes, Endocrinology and Metabolism, City of Hope National Medical Center, Duarte, CA 91010, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rudruidee","family":"Karnchanasorn","sequence":"additional","affiliation":[{"name":"Division of Endocrinology, Department of Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3350-6548","authenticated-orcid":false,"given":"Horng-Yih","family":"Ou","sequence":"additional","affiliation":[{"name":"Division of Endocrinology and Metabolism, Department of Internal Medicine, National Cheng-Kung University Medical College and Hospital, Tainan 704, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Raynald","family":"Samoa","sequence":"additional","affiliation":[{"name":"Department of Clinical Diabetes, Endocrinology and Metabolism, City of Hope National Medical Center, Duarte, CA 91010, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0978-2662","authenticated-orcid":false,"given":"Lee-Ming","family":"Chuang","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, National Taiwan University Hospital, Taipei 102, Taiwan"},{"name":"Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei 102, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2226-1039","authenticated-orcid":false,"given":"Ken C.","family":"Chiu","sequence":"additional","affiliation":[{"name":"Division of Endocrinology, Metabolism and Nutrition, Department of Internal Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1016\/j.amepre.2018.05.018","article-title":"Trends in the Prevalence of Diabetes Among U.S. Adults: 1999\u20132016","volume":"55","author":"Fang","year":"2018","journal-title":"Am. 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