Glucose Tolerance Test (2 Specimens), plasma (Standard) [OGTT (2 samples)]

BC0145

Synonym(s):
Specimen Container
Sodium fluoride tube (Adult)
Fluoride heparin tube (Paeds)
Specimen Requirement
Collect blood to the mark in specimen tube.

The OGTT should be preceded by at least 3 days of adequate carbohydrate diet.
It should be performed in the morning after the patient fasted at least 10 hours(but no longer than 16 hours).
Adult: 75g load.
Child: 1.75g/kg

Invert blood 5 times after blood collection ensures the anticoagulant is well mixed with the blood. This will ensure results are reliable.
 
Specimen Storage/Transport
OGTT timed specimens may be sent together or separately to the laboratory.
Orderable as Urgent? Yes
Turn Around Time
Average 2 hrs (1 - 3 hrs)
Reference Value(s)
Fasting: <= 6.0 mmol/L
120 minutes: < 7.7 mmol/L

Fasting (mmol/L)
Impaired fasting glucose (IFG) : 6.1 – 6.9
Impaired glucose tolerance (IGT) : < 7.0
Diabetes: >= 7.0

2-hour (mmol/L)
Impaired fasting glucose (IFG) : < 7.8 (if measured)
Impaired glucose tolerance (IGT) : 7.8 – 11.0
Diabetes: >= 11.1
Testing Laboratory Location KKH
Laboratory Clinical Chemistry
Contact Number 6394 1383
Day and Time Performed
Mon to Fri: 0800 hr - 1730 hr
Sat: 0800 hr - 1230hr
Orderable on CPOE? Yes
Downtime Form

Clinical Chemistry - Form A

Additional Information
Critical Result:
OGTT (fasting) - > 10mmol/L
OGTT (2 hr) - > 15 mmol/L

Change History Notes

  • 19 Oct 2021 03:55 PM

    ​Updated Specimen Requirement, Specimen Storage, Reference Value(s) and A dditional Information.

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Last Updated - 05 Apr 2025