Abstract: Objective To explore the optimal threshold of HbA1c in the diagnosis of prediabetes in obese children, in order to provide reference for HbA1c in the diagnosis of prediabetes in obese children in China. Methods A retrospective cross-sectional study was conducted.Totally 191 obese children diagnosed in the Department of Endocrinology, Ningbo Women and Children's Hospital were enrolled in this study from June 2018 to May 2021.Oral glucose tolerance test (OGTT) was performed 8 hours after fasting, and fasting blood glucose (FPG) and 2 h post load blood glucose (2 h PG), and HbA1c were tested.According to the diagnostic criteria of the American Diabetes Association in 2020, the participants were divided into the non-prediabetes group and the prediabetes group.The level of HbA1c was compared between the two groups, and ROC curve of HbA1c for the diagnosis of prediabetes was drawn.The diagnosis value of area under curve (AUC) and the sensitivity and specificity of different thresholds were calculated, so as to reveal the optimal threshold for diagnosis. Results According to the OGTT results, children diagnosed with diabetes were excluded, then the participants were divided into two groups, with 142 in the non-prediabetes group (77.6%) and 41 in the prediabetes group (22.4%).After correcting confounding factors by propensity score matching, 100 patients were included in the model, including 63 in the non-prediabetes group and 37 in the prediabetes group.The level of HbA1c of children in non-prediabetes group [(5.52±0.34)%] was significantly lower than that in prediabetes group[(5.69±0.39)%] (t=2.247,P=0.027).ROC curve indicated that area under the curve (AUC) of HbA1c in predicting prediabetes was 0.625 with the optimal threshold of 5.45%, the corresponding sensitivity and specificity was 73.0% and 66.7%, respectively. Conclusion It is speculated that the optimal threshold value of HbA1c for the diagnosis of prediabetes in obese children is 5.45%.

Key words: prediabetes, obesity, HbA1c, children

摘要： 目的 探究糖化血红蛋白(HbA1c)诊断肥胖儿童糖尿病前期的最佳阈值,以期为我国肥胖儿童HbA1c诊断糖尿病前期的开展提供参考。方法 本研究为回顾性样本的横断面研究。选取2018年6月-2021年5月在宁波市妇女儿童医院内分泌科住院部诊断为肥胖的儿童191例,均于空腹8 h后行口服葡萄糖耐量试验(OGTT),记录空腹血糖(FPG)、负荷后2 h血糖(2 h PG),并测定糖化血红蛋白(HbA1c)水平。根据2020年美国糖尿病学会的诊断标准分为非糖尿病前期组和糖尿病前期组,比较两组之间HbA1c水平,绘制HbA1c诊断糖尿病前期的ROC曲线,计算曲线下面积(AUC)及不同阈值的敏感度和特异度,揭示诊断的最佳阈值。结果 根据OGTT结果,去除确诊为糖尿病的儿童并分组,183例中非糖尿病前期组 142例(77.6%),糖尿病前期组 41例(22.4%)。采用倾向评分匹配法校正混杂因素后共100例进入模型,其中非糖尿病前期组63例,糖尿病前期组37例。非糖尿病前期组HbA1c水平[(5.52±0.34)%]低于糖尿病前期组[(5.69±0.39)%],差异有统计学意义(t=2.247,P=0.027)。通过ROC曲线得出HbA1c诊断糖尿病前期的AUC为0.625。最佳阈值为5.45%,对应的敏感度73.0%,特异度66.7%。结论 推测HbA1c在肥胖儿童中诊断糖尿病前期的最佳阈值为5.45%。

关键词: 糖尿病前期, 肥胖, 糖化血红蛋白, 儿童