Fasting plasma glucose test

The fasting plasma glucose (FPG) test can also be called as fasting blood sugar test, which measure blood sugar or glucose levels and is used in diabetes diagnosis. It is simple, relatively reliable and inexpensive test for diabetes diagnosis.

Why Fasting blood sugar test

Fasting triggers glucagon hormone, when there is no enough glucose in blood for energy. Glucagon hormone is produced by the pancreas and it instructs the liver to convert stored glucogen to glucose and release it into the bloodstream for energy requirements.

Once liver releases glucose into the bloodstream, normal body immediately releases insulin to prevent hyperglycemia (high blood glucose). However for diabetics, enough insulin is not released or not proper use of available insulin, thus fasting blood glucose levels will stay high.

Fasting Plasma Glucose Test procedure

This FPG test is performed only after a 12 to 14 hours of fasting (must not to eat or drink any think except water for 12 to 14 hours). Because of this prolong fasting; the test is usually done in the morning for our convenience.

Blood glucose levels

FPG tell us blood glucose level in

milligrams per deciliter (mg/dl), is the unit to measure that shows ‘x’ milligrams of glucose in the blood plasma per deciliter of blood, Blood glucose level in mg/dl is the unit used in United States.
millimoles per liter (mmol/L), is the unit of measure that shows 'x' mmol concentration of glucose in the blood plasma per liter of blood. In most part of the world, except United States uses this unit for blood glucose test results.

Normal blood glucose levels
Blood glucose level of 70 mg/dl to 99 mg/dl is considered as normal range.
Blood glucose level of 3.89 to 5.5 mmol/L is considered as normal range

Pre-diabetes blood glucose levels
Blood glucose level of 100 mg/dl to126 mg/dl suggests pre diabetes
Blood glucose level of 5.56 to 7 mmol/L suggests pre diabetes
Pre-diabetes is called by impaired fasting glucose, indicating an increased risk of developing type 2 diabetes.

Diabetes blood glucose levels
Blood glucose level of higher than 126 mg/dl confirmed as diabetes.
Blood glucose level of higher than 7 mmol/L confirmed as diabetes.

Hypoglycemia blood glucose levels
Blood glucose levels lower than 70 mg/dl is considered as hypoglycemia.
Blood glucose levels lower than 3.89 mmol/L is considered as hypoglycemia.

Even if the results are within the normal range, additional testing may be ordered to determine if a person has additional risk factors for diabetes, such as high body mass index (BMI), or if exhibits other symptoms of diabetes.

Also if the test result confirms diabetes at the border line level, then doctor may order another test on another day to reconfirm diabetes.

Why Fasting blood sugar test

Next: Oral glucose tolerance test