Test Code GTT2HR Glucose Tolerance, 2 Hour, Plasma
Methodology
Hexokinase, Ultraviolet (UV)
Performing Laboratory
St. Clair Hospital Laboratory
Specimen Requirements
1 mL of Lithium Heparin plasma
- Preferred Specimen: Light Green Plasma Seperator Tube (PST)
- Acceptable Specimen: Dark Green Lithium Heparin tube
Centrifuge blood as soon as possible, or send unspun blood to laboratory within 4 hours of draw. Avoid hemolysis. Protect specimen from light.
Note: Do not uncap tube once specimen is drawn.
Reference Values
65-99 mg/dL (fasting)
<140 mg/dL (2 hour)
CRITERIA FOR DIAGNOSIS OF DIABETES MELLITUS
1. Symptoms of diabetes mellitus and any of the following on 2 different days during the oral glucose tolerance test as per World Health Organization specifications:
≥200 mg/dL (casual plasma glucose)
≥126 mg/dL (fasting plasma glucose)
≥200 mg/dL (2 hour plasma glucose)
2. Acute metabolic decompensation with hyperglycemia
145 mg/dL (3 hour)
IMPAIRED GLUCOSE TOLERANCE
100-125 mg/dL (fasting)
140-199 mg/dL (2 hour)
Day(s) Test Set Up
Monday through Saturday