Iranian Journal of

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.

Background: LADA is a subgroup of type 1 diabetes mellitus characterized by its age at diagnosis being more than 30 years, presence of Glutamic Acid Decarboxylase₆₅ (GAD₆₅) autoantibody, and insulin independency in the first 6 months of diagnosis. Our aim was to determine the prevalence and predictors of LADA in a large population-based drug naïve newly diagnosed adult diabetics of Tehran urban population.

Methods: In this cross-sectional study, all newly diagnosed diabetics of Tehran Lipid and Glucose Study aged more than 30 years who were not initialy treated with insulin were tested for GAD antibody titer. Thirty two GAD antibody positive (LADA) and 556 GAD antidody negative patients (type 2 diabetics) were found and compared for anthropometric, clinical and laboratory features.

Results: Mean age of all 588 cases was 54.2±11.6. The prevalence of LADA was %5.44 (CI %95: %3.6-%7.3). Age, sex, BMI, family history of diabetes, diastolic blood pressure, glucose and lipid profile and the prevalence of metabolic syndrome were similar between LADA and type 2 diabetics. Systolic blood pressure were greater in type 2 diabetics than in LADA group. No model could predict the result of GAD antibody measurement.

Conclusion: autoimmune process is present in early stages of diabetes in %5.4 of newly diagnosed adult diabetics assumed to suffer type 2 diabetes mellitus. Using clinical and laboratory features, no model could reliably screen these cases. It seems reasonable to test GAD antibody in all such cases to early find persons more probable to have a more rapid process toward pancreas insufficiency.