Discordance between A1C and fasting glucose (FBG) or oral glucose tolerance glucose (OGTT) in the detection of dysglycemia has been observed in multiracial and multiethnic populations. In most instances, A1C under detected diabetes or prediabetes compared to glucose tests. To determine the relationship between FBG, OGTT and A1C for the diagnosis of prediabetes in a Filipino American population we studied 154 self-reported nondiabetic adult subjects from the Filipino Health study living in the U.S. > 3 year. Mean age 42 ± 18 y, BMI 25.8 ± 3.8, 58% female, and 67% with a family history of diabetes. Using ADA criteria, 5 subjects met the diagnosis of diabetes (4 by A1C and 1 by OGTT, the later subject is not included in Table 1) while 61 (40%) had prediabetes. Prevalence of prediabetes was only 6.5% by FBG and 7.1% by OGTT. However, the prediabetes prevalence was 36% by A1C. Kruskal Wallis was used to test the difference in insulin resistance by HOMA-IR and insulin between HbA1C categories. Subjects with an A1C of 5.7-6.4% (41 of whom had normal FBG and OGTT) were significantly more insulin resistant than those with an A1C < 5.7%. This suggests A1C may be a more sensitive test of abnormal glucose regulation in a Filipino population living in the U.S. than FBG or OGTT. Outcome studies assessing progression to diabetes will be needed to confirm this hypothesis.
M.P. Mercado: None. S. Kim: None. E.C. Cutiongco de la Paz: None. M. Seielstad: None. E. Paz-Pacheco: None. E. Murphy: None.
Philippine-California Advanced Research Institutes