GLUCOSE TOLERANCE, 2 HOUR ADA

Mnemonic

GTT2ADA

Synonym

2 Hour Non-OB Oral Glucose Tolerance Test - OGTT - GTT

Includes

Fasting Glucose and 2 hour glucose post 75 gram load glucola

Guidelines

Recommended in the 2010 ADA guidelines.

Specimen Collection Requirements

Collect

Preferred: Plasma, one 4.0 mL gray (sodium fluoride/potassium oxalate) top tube. Also acceptable: Serum or plasma, one 5.0 mL gold (SST), 7.0 mL red or 3.0 mL mint green (lithium heparin, PST) top tube.

Handling

The gold and green top tubes must be delivered to the lab immediately. Allow serum to clot completely at room temperature (minimum: 30 minutes). Preferably, separate serum or plasma from cells within 1 hour of collection. If unable to spin, preferred specimen is gray (sodium fluoride/potassium oxalate) top tube.

Preferred Volume

0.5 mL per specimen

Minimum Volume

0.3 mL per specimen

Transport

Refrigerated (2-8°C)

Rejection Criteria

Grossly hemolyzed specimens

Stability

AFTER SEPARATION FROM CELLS: Ambient (15-25°C): 8 hours; Refrigerated (2-8°C): 3 days; Frozen (at or below -20°C): 1 month

Testing Information

Performed

7 days/week

Method

Colorimetry

Referral Lab

Samaritan Health Services Laboratories

Reference Values

Reference Values

Interpretation provided.

CPT Codes

82947, 82950

Last Updated: Thursday, January 5, 2017 03:42:13 AM