Glucose, Two-hour Postprandial

Casandra

Casandra Test Code LC16025Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 002022CPT Code 82950

Glucose, Two-hour Postprandial

Also known as: Postprandial Sugar, PP Glucose, Two-hour (After Meal)

Clinical Use

Order Test

Use

Only a minority of patients with diabetes mellitus have the classic symptoms of polyuria, polyphagia, polydipsia, and weight loss. The two-hour postprandial glucose is extensively used to establish the diagnosis of diabetes mellitus. It may be used along with FBS to follow patients with impaired glucose tolerance.

Special Instructions

Ensure the patient has consumed an adequate meal or a 75-gram glucose load two hours prior to the test, as per the physician's instructions. The meal should be completed within 15 to 20 minutes. Stressed patients, such as those undergoing surgery, infections, or using corticosteroids, should not take the test. Proper labeling of the specimen with the patient's name and collection time is required to avoid rejection.

Limitations

This test should not be conducted on stressed patients, including those experiencing surgery, infection, or corticosteroid use, as these conditions can affect glucose levels. Specimens lacking proper labeling, especially collection time, may be rejected. The minimum volume provided does not allow for repeat testing, emphasizing the need for accurate and correct sample collection.

Test Details

Methodology

Automated Analyzer (Clinical Chemistry)

Biomarkers

Glucose

Analyte

Glucose level after meal or glucose drink • Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

LOINC Codes

Order Codes

1521-4

Result Codes

1521-4

Result Turnaround Time

1 day

Specimen

Serum

Volume

1 mL

Minimum Volume

0.5 mL

Container

Gel-barrier tube

Collection Instructions

Collect specimen two hours from the beginning of meal. Separate serum or plasma from cells within 45 minutes of venipuncture. Gray-top tubes only, may be submitted without centrifugation. Label tube with patient's name and collection time.

Patient Preparation

Adequate meal or 75-gram glucose load two hours before two-hour postprandial glucose, as specified by the patient's physician. Patient is allowed usual meal (breakfast or lunch). Patient must complete meal within 15 to 20 minutes.