Diabetes Testing

For Type 1 diabetes, symptoms are often sudden and can be life-threatening whereas in Type 2 diabetes, people can have no symptoms, or the symptoms/signs could be seen as part of aging.

Common symptoms include:

• Increased thirst
• Frequent urination
• Fatigue
• Increased appetite
• Slow healing of cuts and wounds
• Blurry vision
• Frequent infections, e.g. urinary or genital tract
• Headaches
• Dizziness
• Unexplained weight loss
• Peripheral neuropathy (a complication of diabetes where there is nerve damage to the hands and feet)
• Nausea, vomiting or abdominal pain may occur with Type 1 diabetes

Diabetes is diagnosed through a combination of laboratory blood tests:

1. Fasting blood glucose:

The most common test that measures glucose (sugar) levels in a person’s blood at a specific point in time after fasting for eight hours (e.g. overnight). It provides an immediate snapshot of blood sugar levels.

• A fasting glucose of 7.0 mmol/L or more indicates diabetes is likely.
• A fasting glucose of 5.5-6.9 mmol/L requires further testing with an oral glucose tolerance test (OGTT).

2. Glycated haemoglobin (HbA1c):

Measures the average blood sugar levels over a period of two to three months, offering a long-term perspective on blood sugar levels. Fasting is not required for this test.

• Normal range (non-diabetic): HbA1c levels are ≤ 5.9%
• Prediabetes range: HbA1c levels between 6.0% and 6.4% indicate a higher risk of developing diabetes
• Diabetes: HbA1c level ≥ 6.5% (confirmed by either a repeat test or blood glucose level in the diabetes range)

3. Non-fasting (random) blood glucose:

Measures glucose (sugar) levels in a person’s blood at a specific point in time when they have not been fasting.

• Glucose of 11.1 mmol/L or more together with symptoms of hyperglycaemia would indicate diabetes.
• Non-fasting glucose of 5.5 -11.0 mmol/L requires further testing with either a fasting glucose or HbA1c.

4. Oral glucose tolerance test (OGTT)

Includes both a fasting and a non-fasting blood glucose test. After the fasting test, the person will consume a sweet drink and their glucose levels will be tested at one-hour and two-hour intervals.

• Diabetes is diagnosed if fasting glucose level is 7.0mmol/L or above, or two-hour level is 11.1 mmol/L or above.
• If the criteria for diabetes is not met, a fasting glucose 6.1 -6.9 mmol/L and/or 2 hour glucose 7.8 -11.0 mmol/L indicates impaired glucose metabolism with a high risk for developing diabetes.

Note: Different criteria is used during pregnancy for the diagnosis of gestational diabetes:

• Fasting plasma glucose ≥ 5.3–6.9 mmol/L
• 1-hour plasma glucose ≥ 10.6 mmol/L
• 2-hour plasma glucose ≥ 9.0–11.0 mmol/L

5. Antibodies testing

An extra blood test to check autoantibodies may be required where Type 1 diabetes is suspected.

Regular HbA1c testing plays a crucial role in assessing long-term blood sugar control and guiding treatment for people living with diabetes. In patients with diabetes, HbA1c is used to provide a more comprehensive or “big picture” view of how well a person’s diabetes is being managed.

The frequency of HbA1c testing depends on several factors, such as the type of diabetes, the treatment plan, and the person's blood glucose control. Typically, doctors can provide a referral for testing every 3-6 months.

For people with established diabetes, the target HbA1c should be individualised, considering age, duration of diabetes, treatments and other medical conditions. This should be discussed with your medical practitioner.

Treatment to lower HbA1c levels may involve lifestyle changes like diet and exercise, medication and/or insulin therapy.

People living with diabetes are eligible for up to four Medicare-funded HbA1c tests per year.

If yes, your doctor is a participant in Clinical Labs’ Continuing Professional Development (CPD) Diabetes Clinical Evaluation Program. This program supports doctors by helping them send out reminder letters to make sure their patients are up-to-date with the blood tests recommended for diabetes monitoring.

This is an optional program for doctors that refer pathology to Clinical Labs. If your doctor is a program participant, you may receive reminder and/or request form letters from them advising you that blood tests recommended for diabetes monitoring is due.

Can you opt out of receiving these letters?

Receiving a pathology request form can save you time. Complete testing before your next practice visit and your doctor will have those valuable results waiting to review with you. If for any reason you would like to opt out of the reminder service, please email us: diabetes@clinicallabs.com.au