LabCorp Test

Glucose Tolerence Test (GTT) Blood Test, 4-Hour, 5 Specimens

Quick Overview

Determines if blood glucose level is within healthy ranges. Screens for, diagnoses, and monitors hyperglycemia, hypoglycemia, diabetes, and pre-diabetes.

Test #090373


Availability: In stock

Also Known As 4 HR Glucose Tolerance, Non-pregnant; Glucose Tolerance 4 HR, Non-pregnant; 4 HR GTT (5 Specimens)
Preparation Fasting for 10-12 hours required. Three days prior to testing discontinue all nonessential medication that can affect glucose metabolism. Check with physician before stopping any medications. This test requires five blood draws. The first will be taken when you arrive at lab. You will then be given a glucose solution to drink. 4 subsequent collections will be taken at 1 hour intervals. You will be required to remain at the lab until the final collection is taken.
Test Results 1-2 days. May take longer based on weather, holiday or lab delays.

A glucose tolerance test measures how well your body’s cells are able to absorb glucose, or sugar, after you ingest a given amount of sugar.

Collection Instructions: 

1. Patient should be instructed to have nothing to eat or drink for at least 8 hours before the test (except for sips of water).

2. Patient should be instructed to refrain from smoking and drinking coffee just before and during test.

3. Draw blood specimen for a fasting glucose.

4. After drawing fasting specimen, give the patient a 75 g dose of glucose (patient must drink entire beverage within 5 minutes).

5. Draw blood specimens at 1 hour, 2 hour,  3 hour and 4 hours post glucose ingestion.


Trusted, Secure, & Confidential

Please wait...