Objective: To evaluate glycated hemoglobing A1c (HbA1c) in diagnosing metabolic syndrome (MS) in Chinese subjects aged over 50 years. Methods: A community-based cross-sectional survey was conducted between October 2010 and January 2011 in Shipai community, Guangzhou. A total of 1 494 subjects aged over 50 years were investigated. Questionnaire survey and physical examination were performed among all participants. Fasting blood samples were obtained to measure plasma glucose (FPG), blood lipids and HbA1c. MS was defined by the criteria of International Diabetes Federation (IDF), National Cholesterol Education Program-Adult Treatment Panel Ⅲ (ATP Ⅲ)(2005) and Chinese Diabetes Society (CDS), respectively. Receiver operating characteristic (ROC) curves were plotted to explore the accuracy of HbA1c for diagnosing MS. Results: After excluding subjects with missing data, the remaining 1 473 subjects had a median age of 61 years (55-68 years). An HbA1c threshold of 6.1% yielded the highest combination of sensitivity (52.1%) and specificity (84.3%) for diagnosing MS. Using HbA1c≥5.7% as definition of dysglycemia, the prevalence of MS (IDF), MS (ATP Ⅲ) and MS (CDS) were 48.7%, 57.1% and 50.8%, respectively. The κ coefficients were 0.853, 0.768 and 0.730, respectively. Using HbA1c≥6.1% as definition of dysglycemia, the prevalences of MS (IDF), MS (ATP Ⅲ) and MS (CDS) were 41.2%, 45.8% and 39.1%, respectively. The κ coefficients were 0.923, 0.880 and 0.881, respectively. The optimal HbA1c threshold with the highest level of agreement according to IDF, ATP Ⅲ and CDS criteria were 6.1%, 6.3% and 6.3%, respectively. Conclusions: An HbA1c threshold of 6.1% showed a high specificity for diagnosing MS in Chinese subjects aged over 50 years in community-based setting. The optimal HbA1c threshold may vary according to different criteria and populations.
目的： 探讨糖化血红蛋白(HbA1c)在社区人群中诊断代谢综合征(MS)的准确性及其切点。 方法： 2010年10月至2011年1月，采用横断面普查设计对广州市石牌社区50岁以上的原始居民(n＝1 494)进行调查，调查对象完成问卷调查、体格检查，空腹采血检测血糖、HbA1c及血脂。MS诊断分别采用国际糖尿病联盟(IDF)、美国胆固醇教育计划成人治疗组第3次报告(ATP Ⅲ)和中华医学会糖尿病学分会(CDS)的标准。绘制受试者工作特征(ROC)曲线判断HbA1c诊断不同标准MS的准确性。 结果： 1 473名数据完整者中位年龄为61(55～68)岁，HbA1c≥6.1%诊断MS(CDS)的准确性最高(敏感度和特异度分别为52.1%和84.3%)。以HbA1c≥5.7%作为高血糖定义时，MS(IDF)、MS(ATP Ⅲ)和MS(CDS)检出率分别为48.7%、57.1%和50.8%，一致性检验的κ值分别为0.853、0.768和0.730。以HbA1c≥6.1%作为高血糖定义时，MS(IDF)、MS(ATP Ⅲ)和MS(CDS)检出率分别为41.2%、45.8%和39.1%，κ值分别为0.923、0.880和0.881。与IDF、ATP Ⅲ和CDS标准一致性最高的切点分别为6.1%、6.3%和6.3%。 结论： HbA1c 6.1%在该社区50岁以上人群中诊断MS特异度较高，HbA1c可代替空腹血糖作为MS中的高血糖定义，但其最佳切点值因MS定义不同而异。.
Keywords: Diagnosis; Hemoglobin A, glycosylated; Metabolic syndrome X.