Application of HbA1C for diagnosing diabetes in Harbin

Abstract

Objective To evaluate the sensitivity and specificity of different HbA1C cutoff points for diabetes diagnosis in high risk outpatients in Harbin. Methods A total of 2 122 high risk outpatients(male 1 032 and female 1 090)for diabetes screening in the Fourth affiliated Hospital of Harbin Medical University from April 2013 to February 2015 were included in this study, with the average age of(49.26±13.00)year. Oral glucose tolerance tests(OGTT)were conducted and HbA1C levels were examined in these patients. The sensitivity and specificity of different HbA1C cutoff points were calculated and a receiver operator characteristic(ROC)curve was then built. Results The average level of HbA1C in these subjects was(6.45±1.72)%. The prevalence of diabetes was 41.85%. The area under ROC curve(AUC)was 0.89 with the optimal cutoff point of HbA1C 6.0% and 0.68 for the highest Yonden index. The sensitivity and specificity of HbA1C 6.0% were 84.01% and 83.67% respectively. The sensitivity and specificity of HbA1C 6.5% were 62.84% and 95.92%, respectively. The AUC of HbA1C≥6.5% was 0.732. Conclusion HbA1C works well as the diagnostic standard for diabetes in high risk outpatients of Harbin city. The cutoff point of HbA1C 6.0% is suitable for screening diabetes in high risk population, and HbA1C 6.5% is appropriate for diabetes diagnosis, with high sensitivity and specificity. (Chin J Endocrinol Metab, 2017, 33: 562-566) Key words: HbA1C; Diabetes; Diagnosing; Cutoff point