Diagnosis of diabetes mellitus and intermediate glucose abnormalities in obese patients based on ADA (1997) and WHO (1985) criteria.
OBJECTIVE
To assess the accuracy of the 1997 ADA criteria for diagnosing diabetes mellitus and related glucose disturbances in comparison with the reference WHO 1985 criteria in obese subjects.


METHODS
In 286 men and 881 women, 15-84 years of age, with obesity (body mass index (BMI) > or = 30 kg/m2), an oral glucose tolerance test (OGTT) was carried out according to WHO standard. Patients were classified into three categories of glucose tolerance using WHO 1985 (Normal Glucose Tolerance (NGT), Impaired Glucose Tolerance (IGT) and Diabetes Mellitus (DM)) and ADA (Normal Fasting Glucose (NFG), Impaired Fasting Glucose (IFG) and DM) criteria. Prevalence of each category was compared and agreement between the two classifications was assessed. The relation between fasting plasma glucose value and diabetes, as diagnosed by WHO 1985 criteria, was studied using various regression models, cumulative frequency curves, Finch method and ROC curve.


RESULTS
Compared with WHO 1985, ADA criteria strongly underestimated the prevalence rate of diabetes (3.7% vs. 10.6%) and intermediate glucose abnormalities (6.0% vs. 22.4%). Agreement between the two classifications was poor (kappa = 0.23). Moreover, many patients defined as glucose-intolerant by the WHO 1985 criteria were shifted to a more favourable metabolic status by ADA criteria. Thus, ADA criteria failed to detect 69% of WHO diabetic patients and 89% with IGT were considered as normal. According to the method, cut-off value of fasting blood glucose for detecting WHO 1985-diagnosed diabetes varied widely, from 5.3 to 6.3 mmol/l and none was satisfactory because of poor sensitivity and positive predictive value.


CONCLUSIONS
The ADA criteria do not appear to be a good substitute for those of the WHO 1985 at identifying diabetes and intermediate glucose abnormalities in an obese population. Since it appears impossible to determine a reliable cut-off value for fasting blood glucose to identify diabetic obese subjects with sufficient sensitivity, our results justify the retention of the OGTT in clinical practice or for epidemiological studies.
Richard
J-L
JL
Department for Nutritional Diseases and Diabetology, Medical Centre, University Hospital of Nîmes, Le Grau du Roi, France. jlr.mtp@wanadoo.fr
Sultan
A
A
Daures
J-P
JP
Vannereau
D
D
Parer-Richard
C
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism*; D001824:Body Constitution; D015992:Body Mass Index; D001835:Body Weight; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000503:physiopathology; D005215:Fasting; D005260:Female; D018149:Glucose Intolerance / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D019518:Postprandial Period; D012955:Societies, Medical; D014481:United States; D014944:World Health Organization
D001786:Blood Glucose