The criteria for the diagnosis of Diabetes Mellitus have recently been updated (1). The changes include adjustments to definitions and classification as well as diagnosis (2). These changes are incorporated into a screening plan supported by Diabetes Australia and the Commonwealth Government (3). A brief summary of the changes and new recommendations follows:
Type 1 and 2 diabetes replace the terms IDDM and NIDDM respectively. Type 1 indicates beta cell destruction, usually leading to absolute insulin deficiency, and type 2 covers a range from predominantly insulin resistance with relative insulin deficiency to a predominantly secretory defect with or without insulin resistance. The category Gestational Diabetes Mellitus is retained as a separate category. Other specific causes of diabetes, eg genetic defects, drug-induced, pancreatic injury, endocrinopathies are listed separately (2).
A new category called "Impaired Fasting Glucose" has been introduced. This category is analogous to "Impaired Glucose Tolerance" in indicating a metabolic stage between normal glucose homeostasis and diabetes. These states are risk factors for the development of diabetes and cardiovascular disease. Impaired Fasting Glucose is defined by a fasting glucose concentration between 6.1 and 6.9 mmol/L (inclusive).
Change to the diagnostic criteria
The concentration of glucose in a fasting plasma sample required for diagnosis of diabetes has been lowered from 7.8 to 7.0 mmol/L.top of page)
Diabetes Mellitus is diagnosed if any of the following criteria are satisfied:
In the absence of unequivocal symptoms, or if the glucose level is borderline, diagnosis by criteria 1 or 2 should be confirmed by repeat testing on a separate day.
Impaired Glucose Tolerance is diagnosed if a plasma glucose result 2 hours after a 75g glucose load is between 7.8 and 11.0 mmol/L (inclusive).
Impaired Fasting Glucose is diagnosed if a fasting plasma glucose result is between 6.1 and 6.9 mmol/L (inclusive).
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SCREENING FOR TYPE 2 DIABETES (3) (top of page)
Who Should Be Tested
Testing should be performed on anyone with symptoms suggestive of diabetes. Additionally fasting plasma glucose should be performed as a screening test every 5 years in asymptomatic persons from the following groups (3):
Interpretation of Screening Test
If the fasting plasma glucose is:
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For further information please contact Dr Graham Jones on 8382-9100
|Last updated 26/3/2001|