Issue 105 Item 5 WHO vs. ADA Criteria for Diagnosing Diabetes

Identifying diabetes and glucose abnormalities is better achieved with the World Health Organizations (WHO) criteria then the ADA criteria, says researchers. Identifying diabetes mellitus and intermediate glucose abnormalities in an obese population is best achieved with the 1985 World Health Organization (WHO) criteria rather than the 1997 American Diabetes Association (ADA) criteria,, say French researchers.

They suggest the oral glucose tolerance test (OGTT) should be retained for clinical practice and studies because there is no reliable cut-off value for fasting blood glucose sensitive enough to identify diabetic obese patients.

Dr Jean-Louis Richard and colleagues at the University Hospital of Nîmes, and University Institute for Clinical Research, Montpellier, France, carried out WHO standard OGTTs in 286 men and 881 women.

These obese subjects (body mass index of 30 kg/m² or more), aged 15-84 years, were put into three categories of glucose tolerance, the results of which were compared and assessed using WHO and ADA criteria.

Categories used were the WHO’s Normal Glucose Tolerance (NGT), Impaired Glucose Tolerance (IGT) and Diabetes Mellitus (DM) and the ADA’s Normal Fasting Glucose (NFG), Impaired Fasting Glucose (IFG) and DM.

Various regression models, cumulative frequency curves, Finch method and ROC curve according to WHO 1985 criteria were used to investigate the link between diabetes and fasting plasma glucose value.

Compared to the WHO criteria, the ADA criteria was found to strongly underestimate the prevalence rate of diabetes (3.7 percent versus 10.6 percent) and intermediate glucose abnormalities (6.0 percent versus 22.4 percent).

There was poor agreement between the two classifications and many patients moved to a more favourable metabolic status under ADA criteria, having been defined as glucose-intolerant by WHO criteria.

Sixty-nine percent of patients deemed to be diabetic under the WHO criteria were not detected by ADA criteria. And 89 percent of patients deemed to have impaired glucose tolerance under the WHO criteria were found normal by the ADA criteria.

The method showed wide variation in cut-off value of fasting blood glucose for detecting WHO 1985 diagnosed diabetes (5.3 to 6.3 mmol/l). Poor sensitivity and positive predictive value meant none were satisfactory. Diabetic Medicine 19 (4), 292-299