Background: To determine the prevalence and characteristics of subjects with isolated post challenge hyperglycemia (IPH) defined as fasting plasma glucose (FPG) <126 mg/dl and 2-hour plasma glucose (2h-PG) ≥200 mg/dl.

Methods: We evaluated data and results of Oral Glucose Tolerance Test (OGTT) from 9745 participants in Tehran Lipid and Glucose Study (5589 women and 4156 men) aged>20years, without previously diagnosed diabetes mellitus (DM). A logistic regression model for having IPH was developed among subjects with FPG<126mg/dl to predict.

Results: The prevalence of IPH was 3.1% (n=302). 26.5% (n=80) of subjects with IPH had FPG<100mg/dl. The odds ratios for IPH were statistically significant for FPG≥100mg/dl (OR=9.5; 95% CI: 7.1-12.5), age≥40 years (OR=2.6; 95% CI: 1.8 - 3.7), triglycerides≥200 mg/dl (OR=2.1; 95% CI: 1.6-2.7), hypertension (OR=2.0, 95% CI: 1.5-2.6) and abnormal waist circumference (females≥80, males≥90cm) (OR=1.9, 95%CI: 1.3-2.8).

Conclusion: This analysis showed that in Tehran urban subjects with FPG<126 mg/dl, variables such as FPG≥100 mg/dl, older age, hypertriglyceridemia, hypertension and abnormal waist circumference were significantly associated with higher likelihood of IPH; OGTT would hence be recommended in subjects with above mentioned characteristics.