The Postprandial Blood Sugar (PPBS) test measures the glucose in your blood to assess your body’s response to sugar. Glucose, derived from carbohydrate digestion, is the primary source of energy and the main sugar in the bloodstream.

Normally, after eating, blood sugar levels rise quickly, and the pancreas releases insulin. Insulin enables glucose to enter cells, reducing blood sugar and insulin levels, which typically normalize within two hours. In diabetes, this process is impaired, leading to elevated blood sugar due to either insufficient insulin or ineffective insulin use.

By measuring blood sugar levels two hours after a meal, the PPBS test evaluates how well your body controls glucose. Persistently high levels might indicate diabetes, leading to further tests, such as haemoglobin A1c or glucose tolerance tests, to confirm the diagnosis.

Preparing for a PPBS test is simple. Here's what you need to know:

Prerequisites

You do not require fasting before the PPBS test. However, if other tests like haemoglobin A1c, glucose tolerance, or fasting blood glucose are ordered along with the PPBS, then fasting may be needed. Ensure you inform your doctor about any medicines or supplements you’re taking.

The best time to get tested

The test is usually conducted two hours after eating a meal containing at least 75 grams of carbohydrates. Your doctor will instruct you on the timing and any necessary preparations for the test.

Who Should take the PPBS test

The test is suitable for those with symptoms of diabetes like frequent urination, excessive thirst, severe fatigue, unexplained weight loss, or blurred vision. It’s also for individuals with diabetes risk factors, including those with a family history of diabetes, obesity, a sedentary lifestyle, high blood pressure, aged 45 or older, or a history of gestational diabetes. The test is not only useful for diagnosing diabetes and gestational diabetes but also for the monitoring of treatment progress after the diagnosis.

Cautions before taking the PPBS test

No special precautions are needed before the PPBS test. Ensure you finish your meal and avoid smoking or eating snacks during the two hours before the test. Resting before the test is advised since physical activity can raise blood sugar levels.

Your doctor might recommend a PPBS blood test if they suspect diabetes or other conditions disrupting insulin function, especially if you experience symptoms like increased thirst, hunger, blurry vision, fatigue, slow-healing sores, frequent urination, or frequent infections.

People with diabetes risk factors, such as a sedentary lifestyle, family history of diabetes, or obesity, may also need this test as part of routine physical examinations. For those already diagnosed with diabetes, the PPBS test is used to monitor the efficacy of their treatment regimen. Additionally, the PPBS blood test is crucial for diagnosing gestational diabetes during pregnancy, for the good health of both mother and child.

Here's how to interpret the significance of a PPBS test result:

Blood sugar levels above normal two hours after a meal may indicate diabetes. Your doctor will interpret these results based on your age, gender, medical history, and other test results.

Abnormal blood sugar levels may be observed in several conditions including:

• High blood sugar (other than diabetes) can be caused by Cushing syndrome (high cortisol), acute stress (from trauma, heart attack, or stroke), acromegaly (excess growth hormone), pancreatic cancer, pancreatitis (inflammation of the pancreas), or hyperthyroidism (overactive thyroid).

• Low blood sugar may result from severe infections, starvation, insulinomas (insulin-producing tumours), taking too much insulin, excessive alcohol consumption, adrenal insufficiency (underactive adrenal glands), severe liver disease, hypopituitarism (underactive pituitary gland), or hypothyroidism (underactive thyroid).