Sign in →

Test Code PPGN Glucose, Two-hour Postprandial, Plasma

Specimen and Container/Tube

Plasma

Rejection Criteria

N/A.

Specimen Type

Plasma

Preferred Volume

0.5mL

UCMC Collection Instructions

To be followed in order as listed below.
1. Patient Fasting: The patient is to eat no food after
midnight
prior to the test (fasting 8-14 hours before test).
2. Fasting Draw: A fasting glucose sample is collected from the
patient in a gray top (fluoride) Vacutainer tube prior to
Glucocrush® 75 ingestion. The sample is labeled Fasting or
PPG-Fast, with
indication of collection
time.
3. Glucose Beverage Ingestion:
a. Patient drinks the entire bottle of refrigerator-temperature
Glucocrush® 100 solution from a paper cup within 5 minutes.
The
patient may pour the Glucocrush® 75 over ice if so desired.
b. Timing begins the moment the patient starts drinking.
c. In the case of regurgitation, the test is discontinued
unless
the ordering physician can be contacted and decides to have the
test continued. In this case, a note should be made on the
requisition that the test has been performed in spite of the
patient’s regurgitation, per doctor’s instruction.
d. No smoking, gum-chewing, drinking, or eating during test.
The
patient may imbibe small volumes of water. The patient should
remain seated as much of the time as possible.
4. Glucose Beverage Alternative: In some cases, the ordering
physician will ask the patient to have a fasting sample drawn
and
then to ingest a specified meal and return for the 2-hour
sample
collection.
5. Blood Draw:
a. A non-fasting sample is drawn into a gray vacutainer tube 2
hours after finishing Dextol ingestion.
b. Sample is labeled non-fasting or PPG-NONFAST, with
indication of collection time.
6. Storage/Transport:
Samples are kept at room temperature and sent immediately to
Laboratory Service Center.

Refer to Glucose Tolerance testing protocol in the Glucose
Tolerance Testing Collection link

(make the part in blue a link to this document)

Test Usage

This is a screening test for possible diabetes mellitus. The
test is so named because it was common long ago to screen for
diabetes mellitus by measuring blood glucose two hours following a
meal. The test involves measuring plasma glucose from samples taken
before and two hours after a 75 gram oral dose of glucose.
Alternatively, some physicians prescribe a specified meal in place
of the oral glucose.

Doses for children are based on patient weight (1.75 g/kg ideal
body weight, not to exceed 75 gram). However, GTTs on children are
ordinarily performed by the Department of Pediatrics in the
University of Chicago Children’s Hospital.

Critical Results

<40 mg/dL
>500mg/dL

Test Limitations

In the case of regurgitation, the test is discontinued
unless
the ordering physician can be contacted and decides to have the
test continued. In this case, a note should be made on the
requisition that the test has been performed in spite of the
patient���s regurgitation, per doctor���s instruction.
��
No smoking, gum-chewing, drinking, or eating during test.
The
patient may imbibe small volumes of water. The patient should
remain seated as much of the time as possible.

Container/Tube

Gray Top
Na-Fluoride, BD Vacutainer tube or equivalent

Specimen Minimum Volume

0.2mL

Day(s) Performed

24 hours, 7 days a week including holidays.

STAT DAY(S) AND TIME(S) PERFORMED

Not Available

Method Name

Spectrophotometric, Kinetic (hexokinase)

Reference Values

?�In a position statement of the American Diabetes
Association (ADA) on the
Diagnosis and
Classification of Diabetes Mellitus in 2010 [Ref. 2], criteria
for
the provisional diagnosis of diabetes mellitus may be made
when:
a.?�Fasting plasma glucose level of
�?�126
mg/dL?�?�?�OR
b.?�A 2 hour post load glucose level of?�
�?�200 mg/dL during an oral glucose tolerance
test (using a 75 gram glucose load)?�?�?�OR
c.?�Any casual (random) glucose level
of?��?� 200 mg/dL with symptoms of
hyperglycemia or hyperglycemic crisis.
?�

Intermediate states indicative of impaired glucose
homeostasis
that do not meet the diagnostic criteria for diabetes mellitus
include:
a.?�Impaired fasting glucose (IFG),
where fasting plasma glucose levels are 100-125 mg/dL.
b.?�Impaired glucose tolerance test (IGT),
where 2 hour post 75
gram glucose load glucose
levels are 140-199 mg/dL during an oral glucose tolerance test

?�

REFERENCES

1. Classification and diagnosis of diabetes mellitus and
other
categories of glucose intolerances. Diabetes 28:1039-1057,
1979.
2. Diagnosis and Classification of diabetes mellitus. Diabetes
Care
2010; 33 (Suppl 1):S62-S69.

Reject Due To

N/A

Offsite Collection Instructions

To be followed in order as listed below.
1. Patient Fasting: The patient is to eat no food after
midnight
prior to the test (fasting 8-14 hours before test).
2. Fasting Draw: A fasting glucose sample is collected from the
patient in a gray top (fluoride) Vacutainer tube prior to
Glucocrush® 75 ingestion. The sample is labeled Fasting or
PPG-Fast, with
indication of collection
time.
3. Glucose Beverage Ingestion:
a. Patient drinks the entire bottle of refrigerator-temperature
Glucocrush® 100 solution from a paper cup within 5 minutes.
The
patient may pour the Glucocrush® 75 over ice if so desired.
b. Timing begins the moment the patient starts drinking.
c. In the case of regurgitation, the test is discontinued
unless
the ordering physician can be contacted and decides to have the
test continued. In this case, a note should be made on the
requisition that the test has been performed in spite of the
patient’s regurgitation, per doctor’s instruction.
d. No smoking, gum-chewing, drinking, or eating during test.
The
patient may imbibe small volumes of water. The patient should
remain seated as much of the time as possible.
4. Glucose Beverage Alternative: In some cases, the ordering
physician will ask the patient to have a fasting sample drawn
and
then to ingest a specified meal and return for the 2-hour
sample
collection.
5. Blood Draw:
a. A non-fasting sample is drawn into a gray vacutainer tube 2
hours after finishing Dextol ingestion.
b. Sample is labeled non-fasting or PPG-NONFAST, with
indication of collection time.
6. Storage/Transport:
Samples are kept at room temperature and sent immediately to
Laboratory Service Center.

Refer to Glucose Tolerance testing protocol in the Glucose
Tolerance Testing Collection link

(make the part in blue a link to this document)

Stability: Room Temp

8 hours

Stability: Refrigerated

72 hours

Stability: Frozen

Not Stable

Pediatric Volume

0.2mL

Clinical Indications

This is a screening test for possible diabetes mellitus. The
test is so named because it was common long ago to screen for
diabetes mellitus by measuring blood glucose two hours following
a
meal. The test involves measuring plasma glucose from samples
taken
before and two hours after a 75 gram oral dose of glucose.
Alternatively, some physicians prescribe a specified meal in
place
of the oral glucose.

Doses for children are based on patient weight (1.75 g/kg
ideal
body weight, not to exceed 75 gram). However, GTTs on children
are
ordinarily performed by the Department of Pediatrics in the
University of Chicago Children�??s Hospital.

Transport Instructions

To be followed in order as listed below.
1. Patient Fasting: The patient is to eat no food after
midnight
prior to the test (fasting 8-14 hours before test).
2. Fasting Draw: A fasting glucose sample is collected from the
patient in a gray top (fluoride) Vacutainer tube prior to
Glucocrush?? 75 ingestion. The sample is labeled Fasting or
PPG-Fast, with
indication of collection
time.
3. Glucose Beverage Ingestion:
a. Patient drinks the entire bottle of refrigerator-temperature
Glucocrush?? 100 solution from a paper cup within 5 minutes.
The
patient may pour the Glucocrush?? 75 over ice if so desired.
b. Timing begins the moment the patient starts drinking.
c. In the case of regurgitation, the test is discontinued
unless
the ordering physician can be contacted and decides to have the
test continued. In this case, a note should be made on the
requisition that the test has been performed in spite of the
patient�s regurgitation, per doctor�s instruction.
d. No smoking, gum-chewing, drinking, or eating during test.
The
patient may imbibe small volumes of water. The patient should
remain seated as much of the time as possible.
4. Glucose Beverage Alternative: In some cases, the ordering
physician will ask the patient to have a fasting sample drawn
and
then to ingest a specified meal and return for the 2-hour
sample
collection.
5. Blood Draw:
a. A non-fasting sample is drawn into a gray vacutainer tube 2
hours after finishing Dextol ingestion.
b. Sample is labeled non-fasting or PPG-NONFAST, with
indication of collection time.
6. Storage/Transport:
Samples are kept at room temperature and sent immediately to
Laboratory Service Center.

Refer to Glucose Tolerance testing protocol in the Glucose
Tolerance Testing Collection link

(make the part in blue a link to this document)

Specimen Stability

8 hours

Methodology

Spectrophotometric, Kinetic (hexokinase)