[Prevalence of newly diagnosed type 2 diabetes, impaired glucose tolerance and abnormal fasting glucose in a high risk population. Data from the RIAD study using new diagnostic criteria for diabetes].
OBJECTIVE
In 1997 the American Diabetes Association (ADA) introduced new criteria for the diagnosis of type 2 diabetes mellitus, reducing the upper limit of normal fasting blood sugar from 140 to 126 mg/dl. A level of between 110 and 126 < mg/dl (6.1-7.0 mmol/l) was added as a new category, "impaired fasting glucose" (IFG) as an at-risk factor. It was the aim of this study to determine what effect these new criteria will have on the prevalence of type 2 diabetes and other glucose tolerance stages in the German population.


METHODS
The analysis was based on data collected in the "Risk-factors in IGT for atherosclerosis and diabetes" (RIAD) study. 1139 persons of an at-risk population group (aged 40-70 years) were investigated. Most of them were relatives of diabetics and/or themselves had obesity and/or dyslipidaemia. All known diabetics were excluded. All subjects underwent an oral glucose test with 75 g glucose, and plasma glucose values were used for classifying them into different glucose tolerance stages.


RESULTS
According to the new ADA criteria, confirmed by WHO in 1998, the prevalence of type 2 diabetes mellitus was shifted from 11% to 15.1%, that of IGT from 28.8% to 26.2%. An impaired fasting glucose was found in 27.1% of the population cohort, 9.2% of whom had 2-hour plasma glucose levels corresponding to the diabetes criteria. Men in the first age decade (40-49 years) had a 14% prevalence of previously undetected type 2 diabetes, double that in women. Hyperlipidaemia, hypertension and obesity were significantly more common in diabetics and persons with IGT than in normoglycaemic persons.


CONCLUSIONS
The prevalence of previously unknown type 2 diabetes is very high in this at-risk part of the population. Using the criteria for impaired fasting glucose, 9.2% diabetics would remain undetected. We, therefore, support the recommendation that an oral glucose tolerance test be performed in those of the population aged over 45 years and in younger at-risk persons so that any indicated treatment can be initiated at the earliest. Measurement of fasting glucose is adequate in the population aged under 45 years not at special risk.
Köhler
C
C
Institut und Poliklinik für Klinische Stoffwechselforschung, Technische Universität Dresden. ckoehler@rcs.urz.tu-dresden.de
Temelkova-Kurktschiev
T
T
Schaper
F
F
Fücker
K
K
Hanefeld
M
M
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D003925:Diabetic Angiopathies / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005858:Germany / Q000453:epidemiology; D005951:Glucose Tolerance Test; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012307:Risk Factors
D001786:Blood Glucose