GTT stands for Glucose Tolerance Test, which is a medical procedure used to assess how well a patient's body processes glucose.
Purpose of the Glucose Tolerance Test
The primary goal of a Glucose Tolerance Test (GTT) is to determine if a patient can effectively use and store glucose, a type of sugar, normally. [1] This test helps identify various conditions, including:
- Diabetes Mellitus: Assessing the body's ability to regulate blood sugar levels, a key indicator of diabetes.
- Insulin Resistance: Evaluating how well the body responds to insulin, a hormone that helps glucose enter cells.
- Impaired Pancreatic Beta Cell Function: Determining if the pancreatic beta cells, which produce insulin, are functioning properly.
- Reactive Hypoglycemia: Identifying instances where blood sugar levels drop too low after a meal.
- Acromegaly: Detecting this rare hormonal disorder, which can affect glucose metabolism.
- Rarer Disorders of Carbohydrate Metabolism: Screening for unusual conditions that impact how the body processes carbohydrates.
How the GTT Works
While the specific methodology can vary, a Glucose Tolerance Test typically involves the following steps:
- Fasting: The patient is required to fast for a specific period (usually 8-12 hours) before the test.
- Baseline Blood Sample: A blood sample is taken to measure the patient's fasting blood glucose level.
- Glucose Load: The patient drinks a liquid containing a specific amount of glucose.
- Subsequent Blood Samples: Blood samples are drawn at regular intervals (e.g., every 30 minutes, 1 hour, 2 hours, and 3 hours) after the glucose load.
- Analysis: The blood glucose levels are measured in each sample, and the results are analyzed to determine how the patient's body processes glucose over time.
Interpreting GTT Results
The results of the GTT are compared to established normal ranges to determine if the patient has normal glucose tolerance, impaired glucose tolerance (prediabetes), or diabetes. These ranges can vary slightly depending on the specific laboratory and the guidelines used.
