Lab Information Manual

Laboratory:

Clinical Biochemistry (SPECIAL CHEMISTRY)

Test Name:

CLONIDINE STIMULATION TEST - (S)

Test Code: CLDN

Clinical Information:

Description: This procedure is used for the assessment of pediatric patients with suspected growth hormone deficiency.

It is performed in the Pediatric Day Unit at Children’s Hospital.

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:	2 - 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: 1.0 mL

Pediatric Serum: 0.4 mL

Follow lab instruction on the Clonidine Stimulation Requisition Form.

Referral:

Requisition:

Clonidine Stimulation

Reference Values:

Reference Intervals:

Age	Interpretation
<19 y	Peak growth hormone (GH) <6.8 ug/L suggests GH deficiency. Some experts consider peak response 5-10 ug/L as equivocal.
≥ 19 y	Test is not recommended for adult patients. Thresholds for GH deficiency have not been well established.

Growth hormone stimulation test cut-off values are assay dependent and somewhat arbitrary. An inadequate response to at least two stimulation tests, along with auxologic data and clinical assessment consistent with growth hormone deficiency are required to confirm a diagnosis.
Some laboratories recommend a peak value of > 10 ug/L for pediatric patients and suggest values of 5 – 10 ug/L are indeterminate. Values < 5 ug/L are generally considered subnormal.

Availability:

Within 1 Week