[Impact of the new diagnostic criteria proposed by the American Diabetes Association (ADA-97) on the diagnostic prevalence of type 2 diabetes mellitus].

Objective: To compare the diagnostic prevalence of type-2 Diabetes Mellitus (DM2) according to the criteria of the American Diabetes Association (ADA-97) and the WHO.
Design: Crossover descriptive study.
Setting: Urban Health Centre, with a total of 34,234 clinical histories (CH).
Patients: 782 patients, selected through simple random sampling from medical records, aged 45 or over, with a minimum of 5 attendances recorded in their CH and at least 3 attendances in the previous 2 years, were studied.
Measurements and Main Results: Through review of the CH, the variables age, sex and presence of obesity (BMI3 30) were collected. DM2 patients were classified according to WHO criteria, in the three ADA-97 categories: DM2, basal glucaemia altered (BGA) and normal glucaemia (NG) and other situations with altered glucaemia. Mean age was 62.6 (SD 10.8), with 56.4% women. 95 patients (12.1%) had no glucaemia recorded. 15.6% of the patients with WHO criteria (10.7% through oral overload) were diagnosed with DM2, proportion that went up to 18.3% (CI 95% of difference: -1 to 6.4%) on application of the ADA-97 criteria. 12.8% had BGA, 54.1% NG and 2.7% other situations. Additional DM2 cases diagnosed with ADA-97 criteria had a greater proportion of obese people (p = 0.03), with no differences for age and sex found.
Conclusions: We found a 2.7% increase in the prevalence of DM2 diagnosis in the 45 or over population on applying the ADA-97 criteria. These criteria simplify the diagnosis and will enable an appreciable number of patients not diagnosed under WHO criteria (since oral overload is little used) to be diagnosed. This will foment early action to retard micro and macrovascular complications caused by the disease.