Glucose Tolerance Test, 6 specimens

Glucose Tolerance Test, 6 specimens

Test Code

10562
82951, 82952 (x3)
CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.
10562
82951, 82952 (x3)
CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.
Not offered in Quest Nichols Institute - Chantilly, VA | Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano | Quest Nichols Institute -San Juan Capistrano, CA. Please provide SERVICE AREA INFORMATION to find available tests you can order.
In-home collection is not available in your area through Quest Mobile.

Clinical Significance

Glucose Tolerance Test, 6 specimens - This test is used for the routine diagnosis of diabetes in children and the non- pregnant adult. For pregnant females use test code 6745. For appropriate interpretation of this test, the patient must fast overnight and ingest a 75 g load of glucose, immediately after a fasting specimen is obtained. (for children, the glucose load is 1.75 g/kg of body weight, up to 75). The diagnosis of diabetes is made if glucose exceeds 200 mg/dL in the 2 hour specimen and in any preceding specimen.

Test Resources

None found for this test
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Test Details

Patient Preparation

Fasting required. Fasting is defined as no consumption of food or beverage other than water for at least 8 hours before testing.

Methodology

 Spectrophotometry (SP)

Reference Range(s)

American Diabetes Association
 Diagnostic Criteria for Diabetes Mellitus
 
Glucose Value (mg/dL)
Interpretation Fasting 1 Hr Tolerance 2 Hr Tolerance
Normal <100 Not established <140
Impaired Fasting 100-125    
Impaired Tolerance     140-199
Diabetes ≥126*   ≥200*
       
 *Must be confirmed by testing on a subsequent day.   

Specimen 1: 65-99 mg/dL

LOINC® Codes, Performing Laboratory

Service Area must be determined

Fasting required. Fasting is defined as no consumption of food or beverage other than water for at least 8 hours before testing.

Methodology

 Spectrophotometry (SP)

Reference Range(s)

American Diabetes Association
 Diagnostic Criteria for Diabetes Mellitus
 
Glucose Value (mg/dL)
Interpretation Fasting 1 Hr Tolerance 2 Hr Tolerance
Normal <100 Not established <140
Impaired Fasting 100-125    
Impaired Tolerance     140-199
Diabetes ≥126*   ≥200*
       
 *Must be confirmed by testing on a subsequent day.   

Specimen 1: 65-99 mg/dL
Service Area must be determined

Preferred Specimen(s)

Six - 1 mL plasma specimens collected in fluoride/oxalate (gray-top) tubes

Alternative Specimen(s)

Plasma from fluoride/oxalate (gray-top) tube in a plastic screw-cap vial • Serum (separated from cells immediately) in a plastic screw-cap vial • Spun SST • Plasma from lithium heparin (green-top) tube in a plastic screw-cap vial • Plasma from sodium heparin (green-top) tube in a plastic screw-cap vial

Minimum Volume

0.5 mL for each specimen

Collection Instructions

Immediately after a fasting specimen is obtained, have patient ingest a 75 g load of glucose. Draw subsequent specimens per physician's order. If not specified by the physician, draw specimens 1, 2, 3, 4 and 5 hours later. Label each with the specific draw time. Serum and plasma submissions must be separated from cells.

Transport Container

Fluoride/oxalate (gray-top) tubes

Transport Temperature

Room temperature

Specimen Stability

  • Serum:

  • Room temperature: 4 days
  • Refrigerated: 7 days
  • Frozen: 28 days
  • Whole blood (gray-top) tube:
  • Room temperature: 24 hours
  • Refrigerated: 72 hours
  • Frozen: Unacceptable
  • Sodium fluoride plasma:
  • Room temperature: 7 days
  • Refrigerated: 7 days
  • Frozen: 28 days
  • Heparinized plasma:
  • Room temperature: 48 hours
  • Refrigerated: 7 days
  • Frozen: 28 days

Reject Criteria

Unspun SST • Red-top or non-plasma separator (PST) green-top tubes • Anticoagulants other than lithium heparin, sodium heparin or fluoride/oxalate

Setup Schedule

Service Area must be determined

Six - 1 mL plasma specimens collected in fluoride/oxalate (gray-top) tubes

Plasma from fluoride/oxalate (gray-top) tube in a plastic screw-cap vial • Serum (separated from cells immediately) in a plastic screw-cap vial • Spun SST • Plasma from lithium heparin (green-top) tube in a plastic screw-cap vial • Plasma from sodium heparin (green-top) tube in a plastic screw-cap vial
0.5 mL for each specimen

Immediately after a fasting specimen is obtained, have patient ingest a 75 g load of glucose. Draw subsequent specimens per physician's order. If not specified by the physician, draw specimens 1, 2, 3, 4 and 5 hours later. Label each with the specific draw time. Serum and plasma submissions must be separated from cells.

Fluoride/oxalate (gray-top) tubes
Room temperature

Serum:
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 28 days
Whole blood (gray-top) tube:
Room temperature: 24 hours
Refrigerated: 72 hours
Frozen: Unacceptable
Sodium fluoride plasma:
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
Heparinized plasma:
Room temperature: 48 hours
Refrigerated: 7 days
Frozen: 28 days

Unspun SST • Red-top or non-plasma separator (PST) green-top tubes • Anticoagulants other than lithium heparin, sodium heparin or fluoride/oxalate
Service Area must be determined
Not offered in Quest Nichols Institute - Chantilly, VA | Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano | Quest Nichols Institute -San Juan Capistrano, CA. Please provide SERVICE AREA INFORMATION to find available tests you can order.
In-home collection is not available in your area through Quest Mobile.
Test Details

Clinical Significance

Test Resources

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The CPT codes provided are based on AMA guidance and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

This material contains content from LOINC® (http://loinc.org). The LOINC Table, LOINC Table Core are copyright © 1995-2019, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee and is available at no cost under the license at http://loinc.org/license.

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