Diagnosis of Diabetes
A diagnosis of diabetes is given when fasting plasma glucose (Blood drawn from the vein and the liquid part separated for glucose measurement) is 7.0 mmol/L or greater. It is important to stress that a fast of 8 hours or more is necessary and the patient should not be ill or taking drugs e.g. steroid which influence sugar metabolism. We advocate that the first test be confirmed with a repeat blood test.
Glucose Tolerance Test - If the person is given a drink containing 75 grams of glucose a cut-off value of 11.1 mmol/L may be used as an additional criterion, or as the only criterion, for diagnosing diabetes. There is debate among experts as to whether such a glucose drink test is indeed necessary for establishing diagnosis.
Whole Blood Glucose on Capillary Blood, Measuring Through Portable Glucose Meter - usually obtained by finger-prick, the above cut-off values for the diagnosis of diabetes are equal or greater than 6.1 and 11.1mmol/L respectively. Because of the health risks associated with even mild diabetes as well as life insurance and possibly employment implications, we strongly recommend that the diagnosis be corroborated with the measurement of plasma glucose measurement.
Pregnant women - particularly those at high risk, should be screened within the first 12 weeks of pregnancy at the time of booking. Urine testing for glucose as a sole screening procedure is not acceptable. Gestational diabetes is diagnosed when a venous plasma glucose drawn two hours after a 75 grams glucose drink is equal or greater than 8.0 mmol/L. (See Gestational Diabetes).