The fasting plasma glucose cut-point predicting a diabetic 2-h OGTT glucose level depends on the phenotype

Abstract 

To assess the use of fasting plasma glucose (FPG) alone for the screening of diabetes as defined by a 2-h plasma glucose (2-h PG) ⩾11.1 mmol/l following a 75-g oral glucose tolerance test, we collated the results from 17 512 subjects aged 30–89 years without a previous history of diabetes from 12 general population-based Asian studies. The performance of FPG corresponding to the 2-h PG ⩾11.1 mmol/l was characterized. The prevalence of diabetes was 4.0% by the FPG criteria only and 6.0% by the 2-h PG criteria only. The FPG value of 7.0 mmol/l gave a sensitivity for diabetes as defined by a 2-h PG ⩾11.1 mmol/l of 46% and specificity of 99%. The FPG associated with a 2-h PG ⩾11.1 mmol/l with optimal sensitivity and specificity was 5.8 mmol/l (sensitivity 79%, specificity 85%). The optimal FPG cut-point was affected by gender, age, body mass index and the presence of hypertension, and the resulting sensitivity and specificity corresponding to each optimal cut-point changed. The FPG was a specific but insensitive screening test for diabetes defined by 2-h PG ⩾11.1 mmol/l. There seems to be ethnic differences with respect to optimal FPG cut-point, and different screening strategies may be necessary in different parts of the world.

Keywords:  Diagnostic criteria, Diabetes, Fasting glucose, Screening, Asian populations, Oral glucose tolerance test

Abbreviations:  ADA, American diabetes association, AUC, area under the receiver operating characteristic curve, BMI, body mass index, FPG, fasting plasma glucose, IFG, impaired fasting glucose, OGTT, oral glucose tolerance test, ROC, receiver operating characteristic, WHO, World Health Organization, 2-h PG, 2-h plasma glucose