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Epic Test Code LAB3004 Glucose, Fasting

Performing Location(s)

BMC,CRH,LFH,HRK,OCH,FTT,FOX,FCC

Specimen Type

Serum or Plasma

Preferred Container

Gold or Red top tube

Alternate Container

Green or Gray top tube

Blood Tube Draw Volume

Min 50% draw volume  

Minimum Volume to Submit for Testing

0.5 mL Serum or Plasma

  • Multiple test can be performed from this volume. For question please contact the lab at 547-3975.  

Transportation Needs

 Deliver specimen to laboratory within 1 hour of collection if unspun. If not possible see "storage Requirements". 

Storage Requirements

Sample tubes should be centrifuged within 2 hour of collection followed by transfer of the serum (red) or plasma (green top) to a labeled plastic, aliquot tube.

Gold tops do not need to be aliquoted

See Causes of Rejection for temperature requirements.
Gray top tubes do not require centrifugation for transport up to 48 hrs.

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
NaF >3 days Refrigerated
Hemolysis > 500 mg/dL HgB
Lipemia > 700 mg/dL Trig
Bilirubin > 40 mg/dL Bili

Limitations

Hemoglobin of 500 mg/dL [0.31 mmol/L (monomer)]d falsely depresses GLU results by 20 mg/dL [1.12 mmol/L] at 131 mg/dL [7.27 mmol/L] of glucose.
Bilirubin of 40 mg/dL [342 µmol/L] falsely depresses GLU results by 12 mg/dL [0.7 µmol/L] at 124 mg/dL [6.9 µmol/L of glucose.
Lipemic (triglyceride 700 mg/dL [6.86 mmol/L]) samples falsely elevate GLU results by 10 mg/dL [0.56 mmol/L] at 129 mg/dL [7.16 mmol/L] of glucose.
Capillary collected blood may differ from venous due to contamination from hemolysis or interstitial fluid.

Reference Values

Fasting Glucose Reference Ranges
(2012 ADA Clinical Practice Recommendations)
Age Interpretation Value Units High Critical Value Low Critical Value
> 1 week Normal Fasting 70-100

mg/dL

 > 450 <40
≤1 week   Normal Fasting 45-100

mg/dL

 >450 <45

 

 

 

 

The diagnosis of diabetes can be confirmed by:
  • Fasting Glucose ≥ 126 mg/dL on more than one occasion.  Fasting is defined as no caloric intake for at least 8 hours.**
                         OR
  • Symptoms of hyperglycemia and a casual glucose≥200 mg/dL. Casual is defined as any time of day without regard to time since last meal.  The classic symptoms of hyperglycemia include polyuria, polydipsia, and unexplained weight loss.
                         OR
  • 2 hour glucose ≥ 200 mg/dL during an OGTT. Bassett Healthcare Oral GTT Procedure**
 

** In the absence of unequivocal hyperglycemia, these criteria should be confirmed by repeat testing from a laboratory on a different day.

 

Days of Analysis

All

Available STAT

Yes

Additional Information

It is required that the patient be fasting for 8 hours prior to specimen collection

Patient Instructions for Fasting Laboratory Testing

Patient Preparation: Bassett Healthcare Oral GTT Procedure

 

 

Methodology

Beckman AU/Dx Series

CPT Code

82947

Last Updated

27-NOV-24 MS