Comparison of ADA and WHO criteria in detecting glucose disorders in a population-based study: Tehran Lipid and Glucose Study

Many studies have been conducted to compare WHO and ADA criteria for detection of new diabetic patients. This study aims to compare these two criteria in a community-based epidemiological survey in an urban population of the Tehran, Iran.

We studied 3870 men and 5359 women aged 20 years and over, participating in Tehran Lipid and Glucose Study (TLGS). Those with known diabetes were excluded. Blood samples were taken after 12-14 hours’ overnight fast and 2 hours after taking 75gr of glucose orally. Prevalence of showed tolerance categories and the level of agreement (κ statistic) were obtained using WHO and ADA criteria.

Using WHO criteria,6.0% (0.95% CI:5.5-6.5) had type-2 diabetes and 13.0% (12.3-13.7) had IGT (Impaired glucose tolerance). Using ADA, 3.3% (2.9-3.7) had type-2 diabetes and 4.8% (4.4-5.2) had IFG (Impaired fasting glucose)(p<0.05 and <0.001) for diabetes and IGT respectively. 7355 (84%) should concordant results with both criteria. Among 7105 normal subjects by WHO, 153 (2.2%) had IFG or diabetes by ADA, whereas among 8068 normal subjects according to ADA, 1116 (13.8%) had IGT or diabetes by WHO. The level of agreement (κ statistic) between two criteria was 35% (p<0.001). Sensitivity and specificity of ADA criteria were 45.5 and 99.8%, respectively, taking WHO as the gold standard.

Our data shows low agreement between WHO and ADA diagnostic criteria for detection of diabetes. Patients with unknown diabetic IGT are detected more frequently using WHO criteria.