Evidence for diabetes mellitus criteria in 2010 using HbA1c

Abstract

A study was done on the correlation of fasting plasma glucose (FPG) and 2-h PG levels in an oral glucose tolerance test (OGTT 2-h PG) with the glycosylated hemoglobin (HbA1c) value and on the prevalence and incidence of retinopathy in order to determine diabetes mellitus diagnostic criteria using HbA1c in Japanese patients. Participants in this study were 15,191 individuals who underwent OGTT. HbA1c determined by a high-performance liquid chromatography (HPLC) at the time of OGTT was converted by the corresponding National Glycohemoglobin Standardization Program (Seino et al., Diabetol Int 1:2–20, 2010). A high correlation of HbA1c value with FPG and OGTT 2-h PG was observed, and using a regression equation, HbA1c of 6.5 % was calculated to be FPG 124.3 mg/dl and OGTT 2-h PG 199.6 mg/dl, which are consistent with diabetes mellitus diagnostic criteria. The prevalence of all retinopathy was significantly elevated from HbA1c values of 6.1–6.5 %. Also evident was retinopathy excluding microaneurysm, which was elevated significantly from HbA1c values of 6.1–6.5 %. The incidence of all retinopathy was significantly elevated from HbA1c values of 6.1–6.5 %. In view of the above, it can be said that HbA1c of >6.5 % is the most appropriate criteria in Japanese for diagnosing diabetes mellitus. However, from the receiver operator characteristics (ROC) curve, sensitivity of diabetes mellitus was 54.3 % at HbA1c levels of 6.5 % and thus in its diagnosis, the PG level is also very important. It is therefore necessary to take into account both values in the diagnosis of diabetes mellitus.