Along with urine glucose testing, occasional, periodic blood glucose testing in the laboratory is the usual method used to evaluate blood glucose control.

It is recommended that such blood glucose tests should be carried out every month, or more frequently if necessary.

The blood glucose should be estimated in the fasting and/or post-prandial state; a random blood glucose estimation, often, can give valuable information about the immediate status of the patient's glycemic control.

The method used for the determination must be the Glucose Oxidase method; many laboratories continue to use the older, and outdated, Folin-Wu or Somogyi-Nelson methods which should be actively discouraged.

Such occasional blood glucose tests only reflect the PREVAILING blood glucose levels at the PRECISE TIME at which the blood was collected. It CANNOT give a true picture of the ambient blood glucose levels during the intervening period between two tests.

Thus, such occasional blood glucose estimations do NOT allow accurate assessment of the overall GLYCEMIC CONTROL.

It is absolutely essential to understand these drawbacks of evaluating overall blood glucose control.

Major changes in the treatment regimen should never be made on a single occasional blood glucose estimation unless the values are confirmed on repeat testing.