Diagnostic performance of hemoglobin A1c for prediabetes and association with cardiometabolic risk factors in Chinese adolescents without diabetes.

Abstract

To examine the performance of hemoglobin A1c (HbA1c) in diagnosing prediabetes and whether it was associated with cardiometabolic risk factors in Chinese adolescents without known diabetes.
This was a cross-sectional study including 933 adolescents (aged 11-16 years; 46.5% girls) with HbA1c of 6.4% or less and fasting plasma glucose (FPG) of 6.9 mmol/L or less. All participants underwent anthropometric and biochemical examinations. The individuals with an increased HbA1c (5.7%-6.4%) were given a 75-g oral glucose tolerance test (OGTT).
Of 213 subjects with an increased HbA1c or increased FPG (5.6-6.9 mmol/L), only 4.7% (n = 10) met both criteria. Among the 68 students with increased HbA1c who agreed to undergo the OGTT, only 18 subjects (26.5%) were confirmed to be prediabetic, and the receiver operating characteristic curve for HbA1c to identify prediabetes diagnosed by OGTT had an AUC of 0.53, which was not statistically significant (P = 0.69). The waist circumference, FPG, uric acid, and homeostasis assessment model of insulin resistance were correlated with HbA1c (all P < 0.05). Hemoglobin A1c showed significant association with abdominal obesity and dyslipidemia and the clustering of cardiometabolic risk factors (odds ratios, 1.58-1.90; all P < 0.05). The cutoff point of HbA1c was 5.6% with a maximum accuracy in determining multiple cardiometabolic risk factors (sensitivity, 35.1%; specificity, 72.2%).
There is poor agreement between HbA1c and FPG or OGTT in diagnosing prediabetes, but the former was associated with the presence of multiple cardiometabolic risk factors in Chinese adolescents.