Diabetes Metab J.  2012 Apr;36(2):151-156. 10.4093/dmj.2012.36.2.151.

Impact of HbA1c Criterion on the Detection of Subjects with Increased Risk for Diabetes among Health Check-Up Recipients in Korea

  • 1Health Screening and Promotion Center, Asan Medical Center, Seoul, Korea. hkkim0801@amc.seoul.kr


We performed the study to examine the impact of hemoglobin A1c (HbA1c) criterion on the screening of increased risk for diabetes among health check-up subjects in Korea.
We retrospectively analyzed clinical and laboratory data of 37,754 Korean adults (age, 20 to 89 years; 41% women) which were measured during regular health check-ups. After excluding subjects with previously diagnosed diabetes mellitus (n=1,812) and with overt anemia (n=318), 35,624 subjects (21,201 men and 14,423 women) were included in the analysis.
Among the 35,624 subjects, 11,316 (31.8%) subjects were categorized as increased risk for diabetes (IRD) by fasting plasma glucose (FPG) criteria, 6,531 (18.1%) subjects by HbA1c criteria, and 13,556 (38.1%) subjects by combined criteria. Therefore, although HbA1c criteria alone identifies 42% [(11,316-6,531)/11,316] fewer subjects with IRD than does FPG criteria, about 20% [(13,556-11,316)/11,316] more subjects could be detected by including new HbA1c criteria in addition to FPG criteria. Among the 13,556 subjects with IRD, 7,025 (51.8%) met FPG criteria only, 2,240 (16.5%) met HbA1c criteria only, and 4,291 (31.7%) met both criteria. Among subjects with impaired fasting glucose, 65% were normal, 32% were IRD, and 3% were diabetes by HbA1c criterion. In receiver operating characteristic curve analysis, cutoff point of HbA1c with optimal sensitivity and specificity for identifying IRD was 5.4%.
Although HbA1c criteria alone identifies fewer subjects with IRD than does FPG criteria, about 20% more could be detected by addition of HbA1c criteria. Further studies are needed to define optimal cutoff point of HbA1c and to establish screening and management guidelines for IRD.


Fasting plasma glucose; Hemoglobin A, glycosylated; Prediabetic state; Prevalence

MeSH Terms

Diabetes Mellitus
Hemoglobin A, Glycosylated
Mass Screening
Prediabetic State
Retrospective Studies
ROC Curve
Sensitivity and Specificity
Hemoglobin A, Glycosylated


  • Fig. 1 Discordance of newly detected increased risk for diabetes (IRD) as assessed during health check-ups according to fasting plasma glucose (FPG) and HbA1c criteria. FPG criteria, FPG (5.6 to 6.9 mmol/L); HbA1c criteria, HbA1c (5.7% to 6.4%); combined criteria, FPG (5.6 to 6.9 mmol/L) or HbA1c (5.7% to 6.4%).

  • Fig. 2 Prevalence of newly detected increased risk for diabetes in different age groups by fasting plasma glucose (FPG) and HbA1c criteria. FPG criteria, FPG (5.6 to 6.9 mmol/L); HbA1c criteria, HbA1c (5.7% to 6.4%); combined criteria, FPG (5.6 to 6.9 mmol/L) or HbA1c (5.7% to 6.4%).

  • Fig. 3 Comparison of glycemic status categorized by fasting plasma glucose (FPG) and HbA1c criteria (FPG criteria: normal <5.6 mmol/L, pre-diabetes 5.6 to 6.9 mmol/L, diabetes ≥7.0 mmol/L; HbA1c criteria: normal <5.7%, increased risk for diabetes 5.7% to 6.4%, diabetes ≥6.5%).

  • Fig. 4 Receiver operating characteristic curves for HbA1c cutoff point for increased risk of diabetes in reference to fasting plasma glucose-based pre-diabetes (impaired fasting glucose).


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