To research into the impact of the new American Diabetes Association (ADA)
diagnostic criteria on high risk Spanish population, two cross-sectional st
udies involving seven primary health care centers in Catalonia (Spain) were
revised. Individuals aged >40 years with any major risk factor for diabete
s were screened according to the World Health Organization (WHO) rules usin
g a 75 g oral glucose tolerance test to measure fasting plasma glucose (FPG
) and 2 h plasma glucose. The changes on diabetes prevalence and on epidemi
ological characteristics were evaluated applying the ADA criteria on the ba
sis of FPG alone. A total of 970 individuals, 453 males (46.7%), mean age 5
9 years and mean body mass index (BMI) 30.6 kg/m(2) were screened. Among th
e 459 diabetic subjects according to either the WHO or the ADA criteria, 31
4 (68.4%) were classified as having diabetes with respect to both sets of c
riteria (WHO and ADA). The overlap between impaired glucose tolerance (WHO)
and impaired fasting glucose (ADA) diagnoses was 20.7%. Using the ADA crit
eria results in a decrease of the prevalence of diabetes by 1.5% (95% confi
dence interval (CI) = -2.2 to -0.8%). No changes in the diabetic phenotype
(age, sex and BMI) were found. Impaired fasting glucose prevalence was 18.4
% (95% CI = 16-21%). Overall concordance in terms of crude and weighted kap
pa-value was only acceptable (kappa = 0.51 and kappa = 0.61, respectively).
To apply the new ADA diagnostic criteria on high risk Spanish population e
videnced a decrease on diabetes prevalence. Nevertheless, the change of cri
teria undervalued the risk of postprandial hyperglycaemia related to impair
ed glucose tolerance. (C) 1999 Elsevier Science Ireland Ltd. All rights res
erved.