Sign in →

Test Code GLU TOL Glucose Tolerance Testing

Additional Codes

GLUCOSE TOLERANCE TESTING FASTING [LAB081],GLUCOSE TOLERANCE TEST, 1HR [LAB1816],GLUCOSE TOLERANCE TEST, 2HR [LAB1777],

GLUCOSE TOLERANCE TEST, 3HR [LAB1818], GLUCOSE TOLERANCE TEST, 4HR [LAB165],

GLUCOSE TOLERANCE TEST, 5HR [LAB167], GLUCOSE TOLERANCE TEST, 6HR [LAB3099]

Collection Method

Venous collection

Minimum Volume

0.5ml

Container

Grey Top / Sodium Fluoride Potassium Oxalate

Acceptable Specimens

Serum:

  • Gold Top SST
  • Red Top


Plasma:

  • Light Geen Top (lithium heparin)
  • Grey Top(Sodium Fluoride/Potassium Oxalate)

Reference or Target Ranges

Fasting 65-99
1 HR 65-199
2 HR 65-139
3 HR 65-119
4 HR 65-100
5 HR 65-90
6 HR 65-90

 

According to the American Diabetes Association, a fasting glucose level between 100 and 125 mg/dL or a two-hour glucose level between 140 and 199 mg/dL is consistent with impaired glucose regulation (prediabetes). Diabetes Mellitus is diagnosed when one of the following glucose criteria are met or exceeded:

         •  Fasting glucose ≥ 126 mg/dL
         •  Two-hour glucose ≥ 200 mg/dL (following a 75 g oral glucose tolerance 

In the absence of unequivocal hyperglycemia, diagnosis requires two abnormal results from different tests which may be obtained at the same time (e.g. A1C and fasting plasma glucose), or the same test at two different time points.

Reportable Units

mg/dl

Critical Value

<50 mg/dL or >500 mg/dL

Reasons for Rejection

Hemolysis Threshold 1000 mg/dL
Icterus Threshold 60 mg/dL
Lipemia Threshold 1000 mg/dL
Other QNS, contaminated, improperly Labeled, improper specimen type

Specimen Stability

Ambient 8 hours
Refrigerated (4°C to 8°C) 72 hours
Frozen(-40°C to 0°C) N/A

Performance Information

Days and Time Performed 24/7
Expected Turn Around Time Stat: 1 hour
Routine: 4 hours
Stat Availability Yes
Performing Bench CPH Chemistry
Methodology/Method Description Roche Cobas

CPT Codes

82947

Last review/edit date

2025

Patient Preparation

Fasting