Effect of HbA1c combined FPG on screening diabetes in health check-up

Abstract

ObjectiveTo appraise the effectiveness of HbA1c and fasting plasma glucose (FPG) on screening diabetes in health check-up. MethodsA total of 1 337 individuals (male 850, female 487), aged 27 to 91 years with HbA1c test were included. Participates with HbA1c ⩾6.0% or FPG⩾6.1 mmol/L underwent oral glucose tolerance test (OGTT). Diabetes mellitus was diagnosed according to the criteria of WHO in 1999, FPG⩾7.0 mmol/L and/or OGTT 2 h-postload plasm glucose (2 h-PG)⩾11.1 mmol/L. The sensitivity and specificity of HbA1c thresholds and FPG or combination test on screening of diabetes were analyzed. ResultsA total of 842 subjects had HbA1c <6.0%, in which 32 had isolated FPG⩾6.1 mmol/L, of 495 had HbA1c⩾6.0%. Subjects with HbA1c⩾6.0% had significant increased disorder indexes than those with HbA1c<6.0%. 527 subjects who had HbA1c⩾6.0% or FPG⩾6.1 mmol/L underwent OGTT. A total of 234 subjects were newly diagnosed diabetes, including 123 (123/234, 52.56%) with FPG⩾7.0 mmol/L, and 111 subjects (111/234, 47.43%) with isolated 2 h-PG⩾11.1 mmol/L. Among 234 new diabetes, 91.88% (215 subjects) had HbA1c⩾6.3%, and 77.40% (181 subjects) had HbA1c⩾6.5%. HbA1c⩾6.3% combined FPG ⩾7.0 mmol/L increased the positive rate of newly diagnosed diabetes from 91.88% to 96.58%. ConclusionsHbA1c is a practical and convenient tool for screening undiagnosed diabetes in routine health check-up of a large population. Combined use of HbA1c⩾6.3% and/or FPG⩾7.0 mmol/L is efficient for early detection of diabetes.