Spuriously High Prevalence of Prediabetes Diagnosed by HbA^sub 1c^ in Young Indians Partly Explained by Hematological Factors and Iron Deficiency Anemia

• Autores: Pallavi Hardikar, S.M. Joshi, Dattatray Bhat, Deepa Raut, Dinesh Katre, Himangi Lubree, Abhay Jere, Anand Pandit, Caroline Fall, Chittaranjan Yajnik
• Localización: Diabetes care, ISSN-e 0149-5992, Vol. 35, Nº. 4, 2012, págs. 797-802
• Idioma: inglés
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  • To examine the influence of glycemic and nonglycemic parameters on HbA^sub 1c^ concentrations in young adults, the majority of whom had normal glucose tolerance. We compared the diagnosis of normal glucose tolerance, prediabetes, and diabetes between a standard oral glucose tolerance test (OGTT; World Health Organization 2006 criteria) and HbA^sub 1c^ concentrations (American Diabetes Association [ADA] 2009 criteria) in 116 young adults (average age 21.6 years) from the Pune Children's Study. We also studied the contribution of glycemic and nonglycemic determinants to HbA^sub 1c^ concentrations. The OGTT showed that 7.8% of participants were prediabetic and 2.6% were diabetic. By ADA HbA^sub 1c^ criteria, 23.3% were prediabetic and 2.6% were diabetic. The negative predictive value of HbA^sub 1c^ was 93% and the positive predictive value was 20% (only 20% had prediabetes or diabetes according to the OGTT; this figure was 7% in anemic participants). Of participants, 34% were anemic, 37% were iron deficient (ferritin <15 ng/mL), 40% were vitamin B12 deficient (<150 pmol/L), and 22% were folate deficient (<7 nmol/L). On multiple linear regression analysis, HbA^sub 1c^ was predicted by higher 2-h glucose (R^sup 2^ = 25.6%) and lower hemoglobin (R^sup 2^ = 7.7%). When hematological parameters were replaced by ferritin, vitamin B12, and folate, HbA^sub 1c^ was predicted by higher glycemia (R^sup 2^ = 25.6%) and lower ferritin (R^sup 2^ = 4.3%). The use of HbA^sub 1c^ to diagnose prediabetes and diabetes in iron-deficient populations may lead to a spuriously exaggerated prevalence. Further investigation is required before using HbA^sub 1c^ as a screening tool in nutritionally compromised populations.