Diabetes Testing

Regular blood glucose testing by people with diabetes is important to help control it, and also prevent long-term complications. Good control of blood glucose levels can prevent or reduce serious complications.

Frequent testing can show how changes in diet, exercise, medications or weight are having an effect on a patient's diabetes. Close monitoring of blood glucose levels allows control and timely intervention to prevent diabetic complications.

Why is testing important for diabetic patients?

Regular monitoring of blood sugar levels (blood glucose) gives valuable information as to whether the level is within the normal range. If kept in control, this can delay the onset or development of long term diabetic complications, which can even be life-threatening.

People with type 1 and type 2 diabetes can monitor their blood sugar themselves, by using thumb prick blood tests which are available as home kits. Self-monitoring is very important for long-term health. What are the routine tests that are followed?

Regular self testing, recording of blood glucose levels by thumb prick blood tests, laboratory test of HbA1c (glycosylated haemoglobin) level a few times a year should be taken. Other tests that should be performed routinely include: urine test to monitor kidney function; blood fat levels (cholesterol & triglyceride levels), and tests for kidney function. Regular blood pressure measurement and treatment if needed.

Examination of the feet is also necessary, as the patient may not be aware of loss of sensation from early nerve damage.

Also, get eyes tested every 1 to 2 years, depending on test results. How is diabetes and pre-diabetes diagnosed?

The following test are the normal tests whoich are used for diagnosis:

1. Fasting plasma glucose test - This measures the blood glucose with a minimum gap of at least 8 hours without eating. It is best done on an empty stomach in the morning. This test is used to detect diabetes or pre-diabetes. If a person's fasting glucose level is 100 to 125 mg/dL, you have a form of pre-diabetes called impaired fasting glucose (IFG), meaning that one is quite likely to develop type 2 diabetes but does not have it yet. A level of 126 mg/dL or above, confirmed by repeating the test on another day, means that one is diabetic.

99 mg/dL and below - normal, not diabetic
100 mg/dL to 125 mg/dL - pre diabetic
126 mg/dL and above - diabetic.

2. Oral glucose tolerance test (OGTT) -

This measures the blood glucose after one has not eaten for least 8 hours, and then 2 hours after drinking 75 grams glucose-containing beverage. This test is used to diagnose diabetes or pre-diabetes. This test is more sensitive than the fasting plasma glucose test for diagnosing pre-diabetes. If 2 hours after drinking the liquid, the blood glucose level of a person is between 140 and 199 mg/dL, then it a form of pre-diabetes called impaired glucose tolerance or IGT, meaning that one is more likely to develop type 2 diabetes but does not have it yet.

Glucose level of 200 mg/dL or above, confirmed by repeating the test on another day, means that one has diabetes.

139 mg/dL and below - not diabetic, normal
140 mg/dL to 199 mg/dL - pre diabetes
200 mg/dL and above - diabetic

Gestational diabetes is diagnosed based on plasma glucose values measured during the OGTT. Blood glucose levels are checked four times during the test. If the blood glucose levels are above normal at least twice during the test, then the person has gestational diabetes.

3. Random plasma glucose test -

This measures blood glucose without regard to when you ate your last meal. This test, along with an assessment of symptoms, is used to diagnose diabetes, but not pre-diabetes.

A random blood glucose level of 200 mg/dL or more, alongwith presence of the following symptoms, can suggest that one has diabetes:
· increased urination
· increased thirst
· unexplained weight loss

Other associated symptoms include fatigue, blurred vision, increased appetite, and sores that do not heal. Test results are confirmed only after repeating the fasting plasma glucose test or the oral glucose tolerance test on a different day.

What is HbA1c or the glycosylated haemoglobin test?

HbA1c (glycosylated haemoglobin) gets collected in red blood cells when they are produced. This gives a clue about the blood sugar levels over a couple of months - the average lifespan of a red blood cell. Thus, this test shows the average blood glucose level over time, as compared to the thumb prick test, which indicates blood glucose at the time of testing. If the HbA1c level is above 7%, consult a doctor for a better diabetes management plan. If the HbA1c level is above 8%, the doctor may change medication or a more intensive insulin regime be used. The combination of HbA1c test and thumb prick test results give a better indication of variations in blood glucose levels than either test alone.

How often should blood sugar testing be done?

Diabetic patients who are taking insulin injections should self test 3-4 times everyday, especially before retiring to bed. Type 2 diabetic patients on medicines should self test around a few times every week. It is best to check glucose levels first thing in the morning; and before and after meals. Keep changing daily test times to get a better idea of the changes to blood glucose levels.