fasting glucose level is higher than pp

by Revi
(Chennai, india)

Original Question

My fasting blood sugar is 102 mg/dL and my post-meal reading is 92 mg/dL. What does it mean? Am I diabetic?

Quick Answer:

A fasting glucose of 102 mg/dL is mildly elevated if it was a laboratory fasting plasma glucose, while a post-meal value of 92 mg/dL is not high. Having a fasting value higher than a later reading can happen and does not by itself mean you have diabetes.

Answered by:
Dr. Albana Greca, MD, MMedSc

Family Physician, IDF Fellow

Is a Fasting Blood Sugar of 102 Normal?

For a laboratory fasting plasma glucose test, below 100 mg/dL is considered normal. A result from 100–125 mg/dL is in the prediabetes range, while 126 mg/dL or higher may indicate diabetes when confirmed appropriately.

So a fasting value of 102 mg/dL is only slightly above normal and does not diagnose diabetes. The ranges are explained in more detail in our guide to
normal fasting blood sugar levels.

Why Can Fasting Glucose Be Higher Than After Eating?

Although glucose often rises after a meal, it does not have to be higher every time. A lower post-meal reading may occur because of the type and amount of food eaten, physical activity, the timing of the test or normal day-to-day variation.

Early-morning hormones can also cause the liver to release glucose before waking. This is sometimes called the dawn phenomenon and can make morning glucose higher than readings later in the day.

Looking at blood sugar patterns

across the day is usually more informative than comparing only two isolated readings.

Does 102 Fasting and 92 After Eating Mean Diabetes?

No. These two readings alone do not diagnose diabetes. A fasting value of 102 mg/dL is borderline, while 92 mg/dL is not elevated.

Important:

Home glucose meters are useful for monitoring but are not used by themselves to diagnose prediabetes or diabetes. Diagnosis should be based on properly performed laboratory testing.

What Should You Do Next?

Repeat the fasting glucose under normal conditions.

Fast for at least 8 hours before a laboratory fasting test.

If fasting results repeatedly remain at or above 100 mg/dL, ask about an HbA1c.

Tell your doctor if you have a strong family history of diabetes or other risk factors.

A laboratory blood test for diabetes can distinguish a borderline fasting result from true diabetes more reliably than a single home reading.

My Practical Advice

Do not worry about the fact that the fasting number was higher than the post-meal number. The main point is that 102 mg/dL is slightly above the usual fasting range, so it is reasonable to repeat the test and look at the overall pattern rather than one isolated result.