Can HbA1c and 1-Hour Glucose Replace OGTT in Obese Children in Early Detection of Glucose Metabolism Disorders?

Authors : Meliha Esra Bilici, Ayşe Bilge Baklacı

Pages : 307-317

View : 45 | Download : 214

Publication Date : 2025-12-31

Article Type : Research Paper

Abstract :Aim: This study aims to evaluate and compare the diagnostic performance of HbA1c and 1-hour plasma OGTT glucose levels for identifying glucose metabolism disorders (prediabetes or diabetes) in obese children and adolescents. Material and Methods: Children aged 6–18 years with obesity who underwent OGTT between April 2021 and September 2025 were included, yielding a total of 98 cases in the study cohort. Participants were primarily categorized according to American Diabetes Association (ADA) criteria into two main groups: Normal glucose metabolism (NGM, n=55) and Glucose metabolism disorder (GMD, n=43), which included both prediabetes (n=36) and diabetes mellitus (n=7). Anthropometric and biochemical parameters were compared between groups using appropriate parametric or nonparametric tests. The diagnostic performance of HbA1c and 1-hour OGTT-PG (≥155 mg/dL) for detecting GMD was evaluated using receiver operating characteristic (ROC) curve analysis, sensitivity, specificity, and agreement (Cohen’s kappa) with the OGTT-based diagnosis.. Results: BMI SDS was significantly higher in the GMD group compared to the NGM group (2.6 ± 1.5 vs. 2.1 ± 1.4, p = 0.012). The 1-hour OGTT-PG level showed excellent discriminative ability for identifying GMD (AUC = 0.835, p < 0.001), with a sensitivity of 65.1% and specificity of 87.3% at the ≥155 mg/dL cut-off. In contrast, HbA1c demonstrated weak discriminative ability for GMD (AUC= 0.598, p = 0.080). Agreement between 1-hour OGTT-PG and OGTT-based diagnosis was moderate (κ = 0.47, p < 0.001), whereas HbA1c alone did not show statistically significant concordance (κ = 0.136, p = 0.146). Conclusion: In children with obesity, the 1-hour OGTT-PG level is a more sensitive and accurate marker for identifying glucose metabolism disorders than HbA1c. Incorporating the 1-hour OGTT-PG measurement into the assessment of high-risk pediatric populations may facilitate the earlier detection of dysglycemia.
Keywords : HbA1c, 1 saatlik OGTT glukozu, OGTT, Prediyabet, Çocukluk çağı obezitesi, ROC analizi

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