Age and ethnic background may affect diabetes screening

Although the American Diabetes Association supports the use of the hemoglobin A1c blood test as a way of diagnosing type 2 diabetes, a new study has revealed that it may not accurately identify the disease among elderly Asians .
The American Diabetes Association recommends that the test is effective when physicians rely on a cut-off reading of 6.5 per cent or more to show the presence of diabetes. However, the research found that for a group of Asian participants from the ages of 20 to 93 years, the 6.5 per cent cut-off missed many instances of the condition, and may actually contribute to an under-diagnosis of diabetes with increasing frequency as Asian patients get older.
Hemoglobin A1c has traditionally been used for monitoring a diabetic’s long-term blood sugar levels, and the test is simpler and faster than the plasma glucose and the glucose tolerance tests.
Endocrinologist Tunn Lin Tay commented that “The hemoglobin A1c is a useful and convenient screening test for diabetes. However, we may need age-specific reference ranges, rather than using a single cut-off level across the board.”
The study screened 90 primarily Chinese patients with no previous history of diabetes, and found that the standard oral glucose test discovered 40 cases of type 2 diabetes, while the A1c test was less and less accurate as the patients’ ages rose, only diagnosing about 55 per cent of the cases among participants over the age of 72.
Tay reflected that “If clinicians screen elderly patients – especially Asians – using the hemoglobin A1c test, they should confirm the diagnosis using the oral glucose tolerance test .”