Background: Although glucose intolerance (GI) is diagnosed by fasting and 2h plasma glucose (PG) levels during a 75g OGTT, the upper limit of 1h PG level remains to be undefined in subjects with NGT. Previous report focusing on changes from NGT + IGT to diabetes has reported that 1h PG with ≥155 mg/dl is the risk for future diabetes in the world. However, IGT is well known as a risk factor for cardiovascular disease, few studies have focused on changes from NGT to GI. We therefore conducted a 5-year prospective study intended for NGT subjects to clarify the best predictor of the development of GI.
Methods: To diagnose GI, we performed a 75gOGTT. We enrolled 1383 NGT subjects from The Toon Health Study. Finally, we analyzed 981 individuals with NGT who had a repeat health checkup. To investigate valuable predictive factors of progression of GI, we performed ROC curve analyses and compared fasting PG, 1h post OGTT, 2h post OGTT, and HbA1c.
Results: ROC curve analyses revealed that 1h post OGTT was the best predictor of the development of GI in NGT (sensitivity 66%, specificity 74%, at a cutoff value of 149 mg/dl). In NGT with 1h PG>149mg/dl, odd ratio for the development of GI was 4.7 (95% CI: 3.25-6.80) compared to the reference after adjustment for age, sex, and BMI (p<0.0001).
Conclusions: PG level at 1h post 75g OGTT was the best predictor of the development of GI in NGT.
M. Takakado: None. Y. Takata: None. T. Hadate: None. Y. Matsushita: None. R. Kawamura: None. K. Maruyama: None. I. Saito: None. H. Osawa: None.