Abstract

Introduction:To determine the clinical traits of subjects with isolated impaired glucose tolerance (isolated-IGT) defined as fasting plasma glucose (FPG)<100 mg/dl and 2-hour plasma glucose (2h-PG) between 140 mg/dl and 200 mg/dl. Materials and Methods: In this cross-sectional study, we evaluated the data and results of oral glucose tolerance test (OGTT) from 8212 participants of the Tehran Lipid and Glucose Study (4742 women and 3470 men) aged≥20 years, without diabetes. Logistic regression models for having isolated-IGT were developed among 7012 subjects with FPG<100 mg/dl to predict isolated-IGT. Results: The overall prevalence of IGT was 13.6% (n=1120) of these subjects, 59.6% (n=668) were isolated-IGT. In the clinical model, the adjusted odds ratios (OR) for having isolated-IGT were statistically significant for age≥40 years (2.6), hypertension (1.9), overweight (1.7) or obesity (2.2), family history of diabetes (1.3), and female gender (1.2). Adding the lipid profiles to the clinical model increased the area under the receiver-operating characteristics curve (AUC) only slightly (72.5% vs. 71.4%, P=0.001). The other clinical model including waist circumference had similar predictive power compared to the clinical model including female gender (AUC: 71.7 vs. 71.4, P=0.15). Conclusion: This analysis showed that in Tehranian adults with FPG<100 mg/dl, female gender, older age, family history of diabetes, overweight and obesity, and hypertension were significantly associated with a higher likelihood of isolated-IGT OGTT should hence be recommended in subjects with the above mentioned characteristics.