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Test Code GLU TOL 1HR Glucose Tolerance Test, 1HR

Additional Codes

GLUCOSE TOLERANCE TEST, 1HR [LAB1816]

Performing Laboratory

Central Peninsula Hospital

Collection Method

Venipuncture

Container

 

 

Lt Green / Plasma Separator / Lithium Heparin

Specimen Type

Preferred

  • Plasma- Light Green Top

 

Acceptable

  • Serum- Gold Top SST or Red Top
  • NaF/K-Oxalate (gray top tube)

 

Minimum Volume

0.5ml

Specimen Stability

Ambient 8 hours
Refrigerated (4°C to 8°C) 3 days
Frozen(-40°C to 0°C) N/A

 

3 days at 15-25°C only fluoride plasma (grey top)

Reference or Target Ranges

FASTING 65-99 mg/dL
1 HR 65-154 mg/dL

 

Fasting Comment

According to the American Diabetes Association (ADA):
        •      Fasting glucose of 126 or more is diagnostic of diabetes
        •      Fasting glucose of 100–125 indicates impaired fasting glucose (prediabetes)

 

1 Hour Comment

The American Diabetes Association (ADA) has not established a standard reference range for the 1-hour post-glucose tolerance test in non-pregnant individuals, as their guidelines recommend performing a 2-hour 75-g Oral Glucose Tolerance Test (OGTT).

A 1-hour glucose value of 155 or more suggests impaired glucose regulation (prediabetes); additional testing is recommended. 

Reportable Units

mg/dl

Critical Value

<50 mg/dL or >500 mg/dL

Reasons for Rejection

Hemolysis Threshold 1000 mg/dL
Icterus Threshold 60 mg/dL
Lipemia Threshold 1000 mg/dL
Other QNS, contaminated, improperly labeled, improper specimen type

Performance Information

Days and Time Performed 24/7
Expected Turn Around Time Stat: 1 hour
Routine: 4 hours
Stat Availability Yes
Performing Bench CPH Chemistry
Methodology/Method Description Roche Cobas

CPT Codes

82951

Last review/edit date

2025