Comparison of the performance of HbA1c and fasting plasma glucose in identifying dysglycaemic status in Chinese high-risk subjects.

The aim of the present study was to compare the performance of HbA1c and fasting plasma glucose (FPG) in identifying dysglycaemic status among Chinese participants. Fasting plasma glucose and HbA1c were measured in 2318 subjects with at least one risk factor for diabetes but without being previously diagnosed with diabetes. Using HbA1c to diagnose diabetes resulted in the same classification as FPG for 90.5% of the study participants, with 21.0% (n = 487) classified as having diabetes by both FPG and HbA1c and 69.5% (n = 1610) classified as not having diabetes by both FPG and HbA1c. The kappa (κ) coefficient of the FPG criterion with the HbA1c criterion for diabetes was 0.75 (95% confidence interval (CI) 0.72-0.78). The overlap index regarding diabetes diagnosed by FPG or HbA1c was 68.8%. Of 1610 subjects with FPG < 126 mg/dL and HbA1c < 6.5%, 220 (13.7%) had FPG ≥ 100 mg/dL and HbA1c < 5.7%, whereas 277 (17.2%) had FPG < 100 mg/dL and HbA1c ≥ 5.7%. The κ coefficient of the FPG criterion with the HbA1c criterion for prediabetes was 0.30 (95% CI 0.25-0.35). The overlap index between subjects diagnosed as having prediabetes by FPG of 100-125 mg/dL (impaired fasting glucose (IFG)) or HbA1c of 5.7-6.4% (increased HbA1c (IGH)) was 35.9%. The HbA1c criterion demonstrates reasonable concordance with the FPG criterion for diabetes. Hence, HbA1c and FPG can be used for the diagnosis of diabetes. However, the IGH shows limited overlap with IFG for prediabetes. Introduction of the IGH criterion in addition to IFG for the screening of prediabetes could lead to the identification of more people with this condition.

Du TT ，Yin P ，Zhang JH ，Zhang D ，Shi W ，Yu XF ... -  《-》

The association between fasting plasma glucose and glycated hemoglobin in the prediabetes range and future development of hypertension.

Geva M ，Shlomai G ，Berkovich A ，Maor E ，Leibowitz A ，Tenenbaum A ，Grossman E ... -  《Cardiovascular Diabetology》

Discrepancies between Glycosylated Hemoglobin and Fasting Plasma Glucose for Diagnosing Impaired Fasting Glucose and Diabetes Mellitus in Korean Youth and Young Adults.

Glycosylated hemoglobin (HbA1c) has been recommended as a diagnostic test for prediabetes and diabetes. Here, we evaluated the level of agreement between diagnoses based on fasting plasma glucose (FPG) versus HbA1c levels and determined optimal HbA1c cutoff values for these diseases in youth and young adults. The study included 7,332 subjects (n=4,129, aged 10 to 19 years in youth group; and n=3,203 aged 20 to 29 years in young adult group) from the 2011 to 2016 Korea National Health and Nutrition Examination Survey. Prediabetes and diabetes were defined as 100 to 125 mg/dL (impaired fasting glucose [IFG]) and ≥126 mg/dL for FPG (diabetes mellitus [DM] by FPG [DMFPG]), and 5.7% to 6.4% and ≥6.5% for HbA1c, respectively. In the youth group, 32.5% with IFG had an HbA1c level of 5.7% to 6.4%, and 72.2% with DMFPG had an HbA1c ≥6.5%. In the young adult group, 27.5% with IFG had an HbA1c level of 5.7% to 6.4%, and 66.6% with DMFPG had an HbA1c ≥6.5%. Kappa coefficients for agreement between the FPG and HbA1c results were 0.12 for the youth group and 0.19 for the young adult group. In receiver operating characteristic curve analysis, the optimal HbA1c cutoff for IFG and DMFPG were 5.6% and 5.9% in youths and 5.5% and 5.8% in young adults, respectively. Usefulness of HbA1c for diagnosis of IFG and DMFPG in Koreans aged <30 years remains to be determined due to discrepancies between the results of glucose- and HbA1c-based tests. Additional testing might be warranted at lower HbA1c levels to detect IFG and DMFPG in this age group.

Lee J ，Lee YA ，Kim JH ，Lee SY ，Shin CH ，Yang SW ... -  《-》

Screening for diabetes with HbA1c: Test performance of HbA1c compared to fasting plasma glucose among Chinese, Malay and Indian community residents in Singapore.

Lim WY ，Ma S ，Heng D ，Tai ES ，Khoo CM ，Loh TP ... -  《Scientific Reports》

Prevalence of Prediabetes and Undiagnosed Diabetes in Canada (2007-2011) According to Fasting Plasma Glucose and HbA1c Screening Criteria.

To provide the first population-based estimates of prediabetes and undiagnosed type 2 diabetes prevalence in Canada. We combined two fasting subsamples of the Canadian Health Measures Survey, which were restricted to nonpregnant adults ≥20 years of age (N = 3,494). Undiagnosed diabetes was defined as not having self-reported type 2 diabetes but having blood glucose measures that met Canadian guidelines (i.e., fasting plasma glucose [FPG] level of ≥7.0 mmol/L or hemoglobin A1c [HbA1c] level of ≥6.5% [≥48 mmol/mol]). Prediabetes was defined as an FPG level of ≥6.1 and <7.0 mmol/L or an HbA1c level of ≥6.0% and <6.5% (≥42 and <48 mmol/mol). All estimates were weighted using survey sampling weights. CIs were calculated with the bootstrap method. According to FPG levels, the prevalence of undiagnosed type 2 diabetes in Canadian adults was 1.13% (95% CI 0.79, 1.62), contributing to ∼20% of total type 2 diabetes prevalence (5.62 [95% CI 4.52, 6.95]). Compared with FPG levels, the undiagnosed prevalence was greater using HbA1c level as a criterion (3.09% [95% CI 1.97, 4.81]), ∼41% of the total number of cases of diabetes (7.55 [95% CI 5.98, 9.49]). The HbA1c-only criterion resulted in a threefold increase in prediabetes prevalence overall and a sixfold increase among females (FPG 2.22%, HbA1c 13.31%). Screening based on FPG only identified older undiagnosed case patients, with a mean age of 58.7 years (95% CI 59.9, 63.4). Similarly, using HbA1c identified younger individuals with prediabetes, with reduced BMI and waist circumference compared with FPG levels. In this first study of a nationally representative sample with biospecimen measures, we found that the prevalence of undiagnosed type 2 diabetes and prediabetes was significantly higher using HbA1c levels compared with FPG levels. Further evaluation is needed to fully assess the impact of using the HbA1c criterion.

Rosella LC ，Lebenbaum M ，Fitzpatrick T ，Zuk A ，Booth GL ... -  《-》