Growth Hormone Stimulation Test

The growth hormone stimulation test is used for measuring the level of growth hormone in the body. Purpose of conducting this test is to check whether slowed growth of the body results from growth hormone deficiency. This measure is taken after production of growth hormone is stimulated by means of triggers such as arginine. Through this test, the pituitary gland's ability to produce GH is measured. Due to the use of human growth hormone stimulators like arginine, the test is also known as 'Arginine Test'.

HGH Stimulation Test

The procedure for conducting normal GH stimulation test is presented below.

• First step in the procedure is to clean area/site from which blood is drawn out of the veins. Site for placing the IV is generally the back of hand or one which is on the inside of elbow.
• To increase pressure on the vein used for drawing out blood and to make it swell, an elastic band is wrapped around the upper arm.
• Next step in the process after raising the blood pressure is that of inserting the needle inside the vein. After drawing out the first sample of blood, IV is kept in the vein and needle is taken out.
• The purpose of leaving IV in the vein is to avoid rupturing it several times. Five samples of blood are taken from the body. After taking the first sample (at around 6.00-8.00 am), the body is given a dose of arginine. The body is supplied with this chemical continuously for 30 minutes.
• After the 30 minute arginine treatment, body is provided with GH-releasing hormone. The treatments of infusing arginine and GH-releasing hormone are followed by drawing out blood samples. Four blood samples are taken from the body at an interval of 30 minutes each.
• It is not every time that both arginine and GH-releasing hormone are used. Sometimes, only either of the chemical is used. Such a step is taken if the problem of kidney stone is present in the patient. Arginine infusion could be harmful for people with liver or kidney diseases.

Preparing for the Test
The HGH stimulation test requires few precautions to be taken. These precautions need to be kept in mind and thereby, the body prepared for this test.

• One shouldn't eat anything 10-12 hours before the test. Physical activity should also be minimized. Both the food and physical activity act as deterrents in obtaining correct results.
• If necessary, the intake of medications might have to be stopped temporarily with the advice of the doctor.
• It is necessary to relax for about 90 minutes before the test; correct results are obtained by following this instruction.

The normal human growth hormone test level is 7 ng/mL (nanogram per milliliter). However, normal level could be 10 ng/mL for some labs. The intermediate level ranges between 5-10 ng/mL, while anything below 5 ng/mL is considered as subnormal.

The stimulation test is very simple and doesn't cause much pain. Few people may experience moderate pain while others just feel the prick of needle. The site at which blood is drawn out of the body may appear bruised for a few days followed by the test. A slight throbbing could also be experienced. However, one should keep in mind that these problems stay only for a few days. The risks that are associated with growth hormone stimulation test are presented below.

• Some people may feel light-headed after this blood test; few of them might even faint.
• The problem of 'hematoma' i.e. accumulation of blood under the skin might occur.
• Excessive bleeding could be the problem in some of the cases.
• The risk of infection too exists, if proper care is not taken.

The information about risks associated with this test should be useful in taking the necessary measures.