Abstract
AIMS: To investigate whether oral glucose tolerance test (OGTT) 1-hour plasma glucose (1-h PG) concentration can be used as the criterion for diagnosing diabetes mellitus (DM) and pre-diabetes. MATERIALS AND METHODS: Data were collected from 1021 outpatients who completed a 5-point OGTT. The χ(2) test was used to compare the prevalence of diabetes and pre-diabetes based on OGTT 1-h and 2-h PG (2-hour PG) according to different criteria. Cohen's Kappa test and receiver operating characteristic curves (ROC curves) were used to evaluate the diagnostic value of OGTT 1-h PG for diabetes and pre-diabetes. RESULTS: The prevalence rates of diabetes and pre-diabetes were 34.1% and 24.4% based on the American Diabetes Association (ADA) standard, 42.4% and 21.8% when OGTT 2-h PG was replaced with OGTT 1-h PG, and 44.4% and 20.8% when the OGTT 1-h PG was added to the ADA criteria. According to the WHO criteria, the prevalence rates of diabetes and pre-diabetes were 30.4% and 19.2%, 40.5% and 21.8% when OGTT 2-h PG was replaced with OGTT 1-h PG, and 43.9% and 22.2% when the OGTT 1-h PG was added to the WHO criteria. Substituting OGTT 1-h PG for OGTT 2-h PG in the ADA diagnostic strategy still retained good consistency for both diabetes (κ=0.7, 95% CI 70.1% to 78.4%) and pre-diabetes (κ=0.7, 95% CI 64.5% to 75.0%). For diabetes, the area under the curves (AUC) was 93.7% (95% CI 92.2% to 95.1%) for OGTT 1-h PG and 96.1% (95% CI 94.7% to 97.3%) for OGTT 2-h PG. For pre-diabetes, the AUC was 71.8% (95% CI 67.9% to 75.8%) for OGTT 1-h PG and 70.4% (95% CI 65.9% to 74.5%) for OGTT 2-h PG. CONCLUSIONS: The DM prevalence would be significantly higher if the OGTT 1-h PG was adopted as the diagnostic criterion. More prospective studies are needed to validate its clinical utility.