2 Hr Glucose Tolerance (GTT2) |
EPIC Test Name
GLUCOSE TOLERANCE, 2 HREPIC Code
LAB4132Specimen Requirements
| Plasma | |
|---|---|
| Minimum Volume: | 1 mL |
| Collection: | Collect specimens using standard laboratory procedures. |
| Transport: | Room Temperature ASAP |
| Stability: | After separation, Room Temperature: 8 hours at 25 degrees C Refrigerated: 72 hours at 4 degrees C |
| Container: | GREY |
| Processing/Storage: | Separate the sample from the cells ASAP |
| Rejection Causes: | Hemolysis, Insufficient Sample Volume |
| Notes: | Draw a Fasting and 2 hour glucose |
Methods
Photometric assay using HexokinaseTurnaround Time
| Specimen | Turnaround Time | Frequency |
|---|---|---|
| Plasma | 1 day | 24/7 |
Reference Ranges
GLUFG (Fasting) - Photometric assay using Hexokinase
| All Range | Unit |
|---|---|
| 65-99 mg/dL | mg/dL |
GLU2G (2 hour tolerance) - Photometric assay using Hexokinase
| All Range |
|---|
| <140 mg/dL |
Clinical Indications
GTT is performed to check for prediabetes and diabetes and pregnant women for gestational diabetes.For preparation, since activity can affect test results, patients are asked to sit quietly during the entire test, to inform physician about all medicines that are taking, and may be advised to stop taking certain medicines before the test. Patients should not eat, drink, smoke, or do strenuous exercise for at least 8 hours before first blood sampling.
The first blood sample is taken upon arrival testing for fasting blood glucose value. For adult patients with normal body mass, patient will take a small cup of glucose drink containing 75 or 100 grams of glucose within 5 min, additional blood drawn at 2 hours.
Performed
| Lab |
|---|
| Chemistry - Downtown |
Interpretative Information
According to the criteria by International Association of Diabetes and Pregnancy Groups (IADPSG) propose, the diagnosis of GDM is made if at least one value of plasma glucose concentration is ≥ 92, ≥ 180 and ≥ 153 mg/dl, for fasting, one-hour and 2-hour post glucose load glucose values, respectively, after performing a 75 g OGTT.CPT
8295082947
References
1. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy. International Association of Diabetes and Pregnancy Study Groups Consensus Panel., Metzger BE, Gabbe SG, Persson B, Buchanan TA, Catalano PA, Damm P, Dyer AR, Leiva Ad, Hod M, Kitzmiler JL, Lowe LP, McIntyre HD, Oats JJ, Omori Y, Schmidt MI. Diabetes Care. 2010;33:676-82.2. Hyperglycemia and adverse pregnancy outcomes. HAPO Study Cooperative Research Group., Metzger BE, Lowe LP, Dyer AR, Trimble ER, Chaovarindr U, Coustan DR, Hadden DR, McCance DR, Hod M, McIntyre HD, Oats JJ, Persson B, Rogers MS, Sacks DA. N Engl J Med. 2008;358:1991-2002.