Consequences of the new diagnostic criteria for diabetes in older men and women. DECODE Study (Diabetes Epidemiology: Collaborative Analysis of Diagnostic Criteria in Europe).

OBJECTIVE: To evaluate the prevalence of diabetes and the risk of death in older European men and women aged between 60 and 79 years at baseline using the new American Diabetes Association diagnostic criteria for diabetes. RESEARCH DESIGN AND METHODS: The analysis involved existing population-based European studies from the DECODE Study Group (Diabetes Epidemiology: Collaborative Analysis of Diagnostic Criteria in Europe) and involved baseline measures of fasting and 2-h glucose concentrations after a 75-g oral glucose tolerance test (OGTT) and follow-up to determine deaths. This analysis included 4,032 men and 2,207 women who were not previously known to have diabetes and 383 men and 319 women who had established diabetes.
RESULTS: More than half of the diabetic subjects had already been diagnosed, one sixth had a fasting hyperglycemia > or = 7.8 mmol/l (140 mg/dl), one-sixth had a fasting glucose level of 7.0-7.8 mmol/l (126-140 mg/dl), and one-sixth had an isolated postchallenge hyperglycemia (fasting glucose < 7.0 mmol/l and 2-h glucose > or = 11.1 mmol/l [200 g/dl]). Compared with non-diabetic subjects, the hazard ratios for death in diabetic subjects were close to 2 and did not differ significantly according to the method of diagnosis of diabetes, age-group, or sex.
CONCLUSIONS: One-third of the older diabetic subjects who were undiagnosed at baseline had isolated postchallenge hyperglycemia. OGTT screening of the subjects with impaired fasting glucose (6.1-6.9 mmol/l) would reduce this fraction by half. The group with isolated postchallenge hyperglycemia had an elevated risk of mortality similar to that of other diabetic subjects.