Epic Test Code LAB2428 Growth Hormone Supression Test
Performing Location(s)
BMC
Specimen Type
Serum or Plasma(Glucose Only)
Preferred Container
Gold or Red top tube
Alternate Container
Green top tube (glucose only)
Blood Tube Draw Volume
Min 50% draw volume
Minimum Volume to Submit for Testing
0.5 mL Serum or Plasma for Glucose
0.5 mL Serum for Growth Hormone Supression Test
Storage Requirements
Sample tubes should be centrifuged within 2 hour of collection followed by transfer of the serum (red or gold top) or plasma (green top) to a labeled plastic, aliquot tube.
See Causes of Rejection for temperature requirements.
Transportation Needs
Deliver specimen to laboratory within 1 hour of collection if unspun. If not possible see "storage Requirements".
Causes for Rejection
Mislabeled or unlabeled specimen
Less than 50% draw for Vacutainer tubes
Serum stored on clot more than 4 hours
>3 days refrigerated
> 8 hours room temperature
> 5 days Frozen
Hemolysis > 500 mg/dL HgB
Lipemia > 700 mg/dL Trig
Bilirubin > 40 mg/dL Bili
Patient not fasting prior to start of GTGH, stressed patient (surgery, infection, corticosteroids)Specimen not labeled with hourly times
Blood stored on clot for more than 4 hours, gross hemolysis
Reference Values
Diagnosis of Diabetes and Pre-diabetes (2GTT) (75 gram dose) Two or more glucose concentrations must exceed the reference range |
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Specimen | Normal Reference Range (mg/dL) | Pre-Diabetes | Diabetes |
Fasting | 70-100 | 110 - 125 | > 126 |
2 hour | 95 - 130 | 140 - 199 | > 200 |
Diagnosis criteria for 3 Hr GTT (3GTTL) (100 gram dose) Two or more glucose concentrations must exceed the reference range |
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Specimen | Normal Reference Range (mg/dL) |
Fasting | 70-100 |
1 hour | 105 - 160 |
2 hour | 95 - 130 |
3 hour | 70 - 110 |
Glucose Tolerance Tests for OB patients
(2011 ACOG Clinical Practice Recommendations)
Diagnosis of Gestational Diabetes (OBGTT) (75 gram dose) Two or more glucose concentrations must exceed the reference range |
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Specimen | Normal Reference Range (mg/dL) | High Critical Value | Low Critical Value |
Fasting | 70-95 | > 450 | < 40 |
1 hour | 96 -179 | > 450 | < 40 |
2 hour | 100-152 | > 450 | < 40 |
Growth Hormone, Adult Reference Range | |
Males | 0.01 - 0.97 ng/mL |
Females | 0.01 - 3.61 ng/mL |
Reference intervals have not been formally verified in-house for pediatric and adolescent patients. The published literature indicates that reference intervals for adult, pediatric, and adolescent patients are comparable. |
Fasting Glucose Reference Ranges (2012 ADA Clinical Practice Recommendations) |
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Age | Interpretation | Value | High Critical Value | Low Critical Value |
> 1 week | Normal Fasting | 70-100 | <45 | |
≤1 week | Normal Fasting | 45-99 | >450 | <45 |
Available STAT
No
Days of Analysis
M-F
Additional Information
Must preschedule an appointment in the endocrinology Clinic at 607-547-3273.
Patient Preparation:
Patient Instructions for Fasting Laboratory Testing
Test is performed at Bassett Medical Center in Endocrinology Patients having oral glucola need to be monitored by an RN/LPN. Proper preparation of the patient prior to the test also needs to be addressed by the ordering Practitioner and a nurse. The ordering Practitioner is responsible for monitoring the patient during the test.
Patient should be NPO after midnight the night before the test.
Patient should be active and have adequate food intake with at least adequate carbohydrates (at least 150 g. carbohydrate daily) for 3 days prior and then fast 8 hours prior to test.
Many drugs interfere. They include steroids, oral contraceptives, diuretics, and antihypertensive drugs including thiazides, furosemide, anticonvulsants, psychoactive drugs, antituberculous agents, and anti-inflammatory drugs including salicylates.
Patient should not be stressed (e.g. following surgery, with infections or on corticosteroids)
Requisitioning/Labeling Requirements:
When requesting
1. Enter the code LAB2428. When order is released it will expand out into the appropriate number of specimens for the tolerance selected.
2. Specimen labels will print SPECIFIC FOR EACH SPECIMEN IN THE TEST. Be sure to use the correct specimen label for each test and each timed collection.
LINKS:Limitations of Procedure / Contraindications, Reference Range
Includes
Fasting blood glucose and growth hormone followed by glucose and growth hormone levels drawn at timed intervals after administration of a glucose load (see chart)
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Methodology
see individual tests GLUC and GH
CPT Code
see GLUC and GH
Last Updated
18-Mar-22 BHD