Lab Information Manual

Laboratory:

Clinical Biochemistry (SPECIAL CHEMISTRY)

Test Name:

GLUCOSE TOLERANCE TEST FOR GROWTH HORMONE SUPPRESSION - (S)

Test Code: GGH

Clinical Information:

Description: Non-suppressible GH secretion during an oral glucose tolerance test is used for diagnosis of acromegaly and to document remission after surgery.

This procedure is performed in the Endocrinology & Metabolism Clinical Investigation Unit.

Clinical Practice Change - Endocrine Testing and Specialized Endocrinology Requisition Update 15-May-24

Collection Devices:

Preferred Device:	1 - Serum Separator (SST) Tube(s) - Full Tube Collection Serum Separator (SST) Tube(s) - Full Tube Collection Manufacturer: Becton Dickinson Catalogue #: 367986
Alternate Device:	3 - Microtainer(s) - Serum Separator (0.6mL) Microtainer(s) - Serum Separator (0.6mL) Manufacturer: Becton Dickinson & Company Catalogue #: 365967

Serum tubes with no gel are also acceptable.

Specimen Required:

Serum: 2.0 mL

Pediatric Serum: 0.6 mL

Follow lab instruction on the Glucose GH Suppression Requisition Form.

Referral:

Requisition:

OGTT for GH Suppression (R110-10-02C)

Reference Values:

Reference Intervals:

Age

Interpretation

All

Growth Hormone: Suppression <1 ug/L is considered a normal response. Suppressed levels do not exclude acromegaly (false negative rate up to 50%). False positive may be observed in puberty and patients with diabetes, liver disease, kidney disease or anorexia nervosa.

Insulin: Response may vary greatly, may be useful in assessing therapy effectiveness.

Availability:

Within 1 Week