Why Are Fasting Blood Sugars Higher Than Postprandial?

There are several reasons why a fasting blood sugar can be higher than the results of a blood test taken after eating a meal. Understanding these reasons can help determine whether a higher fasting blood sugar is a medical concern.

What is Fasting Blood Sugar?

• Fasting blood sugar measures the amount of glucose in the blood after a person has not eaten for at least eight hours. It is an important gauge to determine if glucose is actually leaving the blood and moving into the cells of the body where it can be processed for energy purposes.

What is Postprandial?

• Postprandial is a term used to describe blood testing that occurs after a person has eaten a meal. It is usually conducted two to three hours later.

Many Causes

• A high fasting blood sugar can result from various issues. These include the dawn phenomenon, too much blood pressure medication, infection and stress.

Dawn Phenomenon

• This is caused by normal hormonal activity working to prepare the body to wake up. Beginning at 4 a.m., the body secretes various hormones aimed at raising blood sugar levels to provide energy to get up and start the day.

Too Much Medication

• Taking too much blood-pressure medication can also raise blood sugar levels. When the body tries to naturally correct an overdose, it raises blood pressure, which is accompanied by additional blood glucose.

Warning

• Do not assume anything from only one blood test. Talk to your medical professional to determine if a high fasting blood sugar result is a health issue for you.