Growth Hormone

Diagnostic Use

GH measurements are used during investigations of short stature, adult GH deficiency, acromegaly, gigantism and assessment of hypothalamic-pituitary function. Single GH estimates are seldom useful. If acromegaly is being considered, IGF-1 is the preferred test.

Department

Endocrinology Lab

Delphic Registration Code

GHI

Laboratory Handling

Separating

Sample should be separated as soon as possible and sent to Endolab same day. If not in Endolab same day, then separate and freeze.

Synonyms

GH
hGH

Turnaround Time

5 days

Test Code

6539

Specimen Type

• Serum
• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Preferred if West Coast

• SST II (Gold Cap)

Acceptable

• SST II (Gold Cap)
• Lithium Heparin - Non-gel (Green Cap)
• Lithium Heparin - Gel (Light Green Cap)
• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

4

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Acceptable

• SST II (Gold Cap)
• Lithium Heparin - Non-gel (Green Cap)
• Lithium Heparin - Gel (Light Green Cap)
• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1

Additional Specimen Information

Pre-Testing Requirements:
Patient should be unstressed and preferably fasted prior to sampling. Repeated sampling, stimulation and suppression tests are usually necessary.

It is essential to state the age of the patient and percentage above ideal body weight in order to facilitate interpretation of results.

Note: Hypothyroidism must be corrected before carrying out tests of growth hormone secretion. Other drugs, particularly progestogens, chlorpromazine, L-Dopa, etc should be avoided.

Specimen Collection Protocols:
See the specific instructions for particular dynamic tests.
Note that all samples, including those in a series, must have individual unique lab ID numbers.

Serum or plasma stability;
Ambient up to 8 hrs
Chilled (2-8deg) 24 hrs
Frozen 1 month

Aliquot Instructions

Sample Type

• Serum
• Plasma

Minimum Volume (ml)

0.5

Transport to Lab

Frozen
If overnight - Frozen

Additional Referral/Aliquot Information

West Coast: If specimen is unable to be separated, take blood on SST and send chilled to Greymouth Lab. At Greymouth lab freeze serum/plasma for transport to CHL.

Interpretation

Raised Values – exercise, stress (physical and psychological), sleep (stage IV), protein foods, arginine, hypoglycaemia, glucagon, L-Dopa, acromegaly, gigantism, some diabetics.
Low Values – (ie impaired response to stimulation tests) hypothyroidism, hypopituitarism, obesity, prepubertal status, bromocriptine, L-Dopa, somatostatin, glucose infusion.

Reference Intervals

GH reference range: (unstressed, no drugs):

Note: GH pulses may exceed reference values. The test is not suitable for samples obtained in pregnancy or under Pegvisomant treatment.

Adults: female   <6 µg/L

male   <0.6 µg/L

Children:  A response to provocative testing of <3 µg/L is indicative of GH

deficiency.

Test Method

Roche ICMA

Non-Funded Test Cost

$22.87 (Exclusive of GST)

Billing Code

6539

Same day testing on request

Contact Information

Enquiry Form