Glucose Tolerance, 5 Hour

Glucose Tolerance 5 Hour

Alternate Test Name

5 Hour Glucose Tolerance
5 Hour GTT
5 Hour Tolerance, Glucose

Epic Mnemonic
Sunquest Mnemonic

LAB167
5GTT

Category

Chemistry

Methodology

Enzymatic; Hexokinase

Test Performance Schedule

Sunday - Saturday

Result Availability

Within 24 hours

Container

Gold top (SST), Green top (lithium heparin) or Lavender top (EDTA) tube

Volume

Pref. Vol.: 1.0 mL serum or plasma
Min. Vol.: 0.3 mL serum or plasma

Collection Instructions

• Routine venipuncture
• Collect at specified times:
» Fasting sample - preglucose dose
» 1 hour sample - post glucose dose
» 2 hour sample - post glucose dose
» 3 hour sample - post glucose dose
» 4 hour sample - post glucose dose
» 5 hour sample - post glucose dose

Gold Top:
• Clot 30 minutes
• Immediately centrifuge 15 minutes
• Within 60 minutes of collection, transfer serum to separate plastic tube
• Refrigerate



DIET INSTRUCTIONS PRIOR TO GLUCOSE TOLERANCE TEST

Transportation Instructions

Refrigerate for up to one week at 2-8° C

Stability

• Room Temperature: 8 hours
• Refrigerated: 3 days

Causes for Rejection

Serum or plasma in contact with cells (unspun) for more than 2 hours,
Gross Icterus

Remarks

Patient Preparation:
• Fasting at least 8 hours; 12-hour fast is preferred; fasting should not exceed 14 hours
• At least 3 days prior to sample collection, ambulatory patients should receive appropriate Lakeland Instruction sheet regarding test preparation and diet requirements
• The patient may drink only water during test
• Dozing, smoking, gum chewing and exercise are not permitted during the test

Additional Test Information:
NOTE: Dosage for children (12 years of age or less) is 1.75g/kg body weight; maximum dose is 75g.

CPT Codes

82951, 82952

Effective/Revised

3/27/2020

Lorum Ipsum Opsom