Sensitivity of A1C to diagnose diabetes is decreased in high-risk older Southeast Asians

Abstract Objective To determine the effect of ageing on the performance of glycosylated haemoglobin A1C (A1C) for the diagnosis of diabetes mellitus (DM) in Southeast Asians. Methods A1C was measured in 511 subjects (mean age of 52.4 years; range 14–93) undergoing the 75-g oral glucose tolerance test (OGTT). Using receiver operating curve (ROC) analysis, the performance of A1C for the diagnosis of diabetes (using different standard criteria) was compared between 4 groups: < 45 ( n = 156), 45–54 ( n = 132), 55–64 ( n = 122), ≥ 65 years ( n = 101). Results Subjects aged ≥ 65 years had the highest false-negative rates with fasting plasma glucose (60.8%) and A1C (35.1%), the smallest area under ROC curve (0.723, 95% CI 0.627–0.820), the lowest sensitivity (58.7%, 95% CI 50.4–65.7) and specificity (71.1%, 95% CI 57.3–82.6) of A1C 6.5%, compared to the younger age groups. Conclusion OGTT is preferable for diagnosis of DM in older Southeast Asian adults.