Glucose Tolerance Test 5 hour (GTT 5hr)

SIM

11435 

CPT

82951; 82952x2 

Synonyms

Glucose Tolerance 5 hour, GTT 5 hour

Specimen Type

Plasma or serum 

Container

3.5 ml Green - Lithium heparin plasma separator 
4.0 ml Gold-top serum separator

Collection Instructions

Collect 5 hours after Glucola.

Volume

2 ml plasma or serum 
Min: 1 ml

Additional Information

None

Patient Preparation

Glucola

Specimen Processing Instructions

Plasma:  Centrifuge at 3380 rpm’s (±100) for a minimum of 10 minutes

Serum:  Allow to clot.  Centrifuge at 3380 rpm’s (±100) for a minimum of 10 minutes.

Centrifuge within 2 hours of collection.

Transport Requirements

Refrigerated

Specimen Stability

Room temperature:  8 hours   Refrigerated: 48 hours 

Rejection Criteria

•  If not centrifuged within 2 hours of collection. 
•  Gross hemolysis

Reference Range

1hr = 90 - 160 mg/dl

2 hr = 70 - 140 mg/dl

3 hr = 70 -100 mg/dl

4 hr = 70 -100 mg/dl

5 hr = 70 -100 mg/dl

Critical Value

<40 mg/dl, >400 mg/dl 

Test Includes

Glucose 

Methodology

Timed endpoint method 

Testing Frequency

Daily, Monday - Sunday 

Reviewed By

Crystal M. Killian

Reviewed Date

3/18/2021

Supplemental