Glucose Tolerance Test, 2 Specimens (75 g)
Use
This test is used for the routine diagnosis of diabetes in children and the non‑pregnant adult. For pregnant females, a different test (Gestational 4 specimens) is indicated. The patient must fast overnight and ingest a 75 g glucose load; a fasting specimen is obtained immediately and a second specimen 2 hours post-load. Diabetes is diagnosed if the fasting glucose is ≥ 126 mg/dL or the 2‑hour specimen is ≥ 200 mg/dL.
Special Instructions
Patient preparation requires fasting (no food or beverage other than water for at least 8 hours) before the fasting specimen. Immediately after fasting draw, administer 75 g glucose, then draw the 2‑hour specimen, labeling each with the draw time. Serum and plasma must be separated from cells.
Limitations
Not provided.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.5 mL
Container
fluoride/oxalate (gray‑top) tube
Causes for Rejection
Unspun serum separator tubes, red‑top or non‑plasma separator green‑top tubes, other anticoagulants
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |
| Frozen | 28 days |