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Glucose Tolerance Test Oral, 5 Hour

Includes:

•2-Hour Fasting, 1 and 2 hour specimens
•3-Hour Fasting, 1, 2 and 3 hour specimens
•5-Hour Fasting, 1, 2, 3, 4 and 5 hour specimens

CPT:

82951, 82952(X3)

Methodology:

Endpoint

Testing Schedule:

Routine, STAT testing available

Report Available:

1 day

Specimen Requirements:

Minimum Volume:

1 mL plasma per collection

Container:

Gray top (sodium fluoride) tube

Collection:

•Overnight fast required.
•A fingerstick glucose is performed by Point of Care testing.
•If Point of Care glucose is >200 mg/dL, contact the laboratory to request the fasting glucose specimen submitted be performed STAT.If this result is >200 mg/dL, the physician is notified to determine if the test should continue.
•If Point of Care glucose is <=200-mg/dL, administer 75 grams oral glucose solution and proceed with obtaining venous specimens at specified hourly intervals (not eating or drinking anything until the test is complete).

Special Instructions and/or Comments:

For children and small adults, it is not advisable to administer 75 gram load.Administer 1.75 grams glucose/kg of body weight (1 kg = 2.2 lb).Contact a Customer Care Specialist at 610-402-8170 for further instructions.

Reference Range:

Fasting:
< 7 days: 47-110 mg/dL
> 7 days 65-99 mg/dL
2 Hour:
> 10 years <140 mg/dL
Diagnostic of Diabetes
Fasting> 10 years >125 mg/dL
2 Hour> 10 years
• Impaired glucose tolerance 140-199 mg/dL
• Diabetes: >199 mg/dL

Critical Values:

•<40 mg/dL
•>400 mg/dL

Clinical Utility:

Used in the evaluation of carbohydrate metabolism.