Is A1C Less Concordant with OGTT in Children as Compared in Adults? Data from a Hispanic Community in Arizona

Abstract

Early efforts to identify hyperglycemia and those at risk for developing type 2 diabetes (T2DM) are warranted. For decades, the diagnosis of T2DM has been based on plasma glucose (PG) criteria but recent recommendations include the use of A1C for identifying hyperglycemia. These recommendations are based upon adult studies and data suggests that A1C may be less concordant in children, as compared to adults. The purpose of our study was to compare A1C, fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT) between adolescents and adults in Hispanic population at disproportionate risk for developing T2DM. Methods: Data from self-identified as Latino, 91 overweight adolescents, and 406 overweight adults were assessed after an overnight fast for A1C, FPG and OGTT results. Receiver Operator Characteristics Curves for A1C vs. any hyperglycemia (prediabetes or diabetes) were then developed. Result: 26 (28.6%) of the adolescents and 209 (51.5%) of adults exhibited hyperglycemia according to FPG and/OGTT. The prevalence of hyperglycemia as defined by an A1C>5.7% was 30.8% in adolescents and 55.6% in adults. Of the 26 adolescents, hyperglycemic on FPG and /or OGTT only 9 had A1C>5.7% for a sensitivity of 34.6%. This in contrast to adults, where the sensitivity of A1C>5.7% was 74.2%. Positive predictive value (PPV) for the A1C threshold of 5.7% was 32.1% in adolescents vs. 73.7% in adults. Conclusion: Concordance of A1C with other measures of hyperglycemia is lower in overweight Hispanic adolescents, as compared to overweight Hispanic adults.