Glucose Tolerance Test (1 Sample)

Function

The Glucose Tolerance Test (GTT) measures the body's ability to metabolize a specific dose of glucose. While a full GTT involves multiple blood draws, a '1 Sample' GTT typically refers to a measurement taken at a specific interval (usually 1 or 2 hours) after consuming a standardized 75g or 50g glucose drink. It evaluates how quickly insulin is released and how effectively it clears glucose from the bloodstream.

Why it is Ordered

This test is a more sensitive indicator of glucose intolerance than a simple fasting glucose test. It is frequently used for:

• Screening for Gestational Diabetes in pregnant women (usually between 24-28 weeks).
• Diagnosing Prediabetes or Type 2 Diabetes when fasting results are borderline.
• Evaluating 'Reactive Hypoglycemia' if the sample is taken later in the process.

Associated Conditions

• Impaired Glucose Tolerance (IGT): A 'prediabetic' state where levels are higher than normal but not yet in the diabetic range.
• Gestational Diabetes Mellitus (GDM): High blood sugar that develops during pregnancy.
• Metabolic Syndrome: A cluster of conditions including high blood sugar, hypertension, and obesity.

Clinical Implications

High results on a GTT indicate that the body is struggling with 'insulin resistance' or insufficient insulin production. Early detection through this test allows for lifestyle interventions (diet/exercise) that can prevent the progression to full-blown Type 2 Diabetes.