How is the Growth Hormone Test Done?

Growth hormone is one of the hormones produced by the pituitary gland in the brain, and it plays a crucial role in the development and growth of individuals, specifically children and teenagers. The body can produce varying amounts of growth hormone, so a doctor may request a test to measure and monitor its levels. So, how is the growth hormone test done?

How is the growth hormone test done?

The growth hormone test is used to evaluate the pituitary gland's function, diagnose deficiencies or excesses of growth hormone, and diagnose and monitor the treatment of acromegaly and gigantism.

This analysis is conducted quite differently from other tests and under careful medical supervision, as measuring its level in the blood once is not informative due to growth hormone being released in pulses. So, how is the growth hormone test done?

The increase or decrease in the body's growth hormone level is analyzed by inhibiting or stimulating its production in specific ways to monitor the pituitary gland's response and hormone levels. Here's further clarification on how this is done:

• How is the growth hormone stimulation test performed?

The growth hormone stimulation test helps diagnose growth hormone deficiency and hypopituitarism. 

This test is conducted for both children and adults in the same manner. Initially, a doctor inserts an IV line into the person's arm or hand, draws a blood sample, and then administers a solution containing a dose of medications that stimulate the pituitary gland to release growth hormone to determine whether the pituitary gland has been stimulated to produce the expected levels of growth hormone. Then, a technician starts taking blood samples approximately every 30 minutes to measure growth hormone levels.

In the past, insulin was used to stimulate the pituitary gland, but it is less commonly used now due to its undesirable side effects and concerns about lowering blood sugar levels. Currently, for children, clonidine, arginine, or glucagon are used, while for adults, macimorelin is used. 

In addition to this test, the doctor requests measuring the levels of:

1. insulin-like growth factor 1 (IGF-1).
2. insulin-like growth factor binding protein 3 (IGFBP-3).

• How is the growth hormone suppression test performed?

The growth hormone suppression test helps diagnose excess growth hormone by giving the patient a dose of glucose and monitoring whether it can suppress growth hormone production. Typically, it's done as follows:

1. First, a blood sample is drawn between 6 - 8 a.m before eating or drinking anything.
2. Then, the patient is asked to drink a glucose solution to avoid nausea slowly, but it must be consumed within 5 minutes for an accurate result.
3. Blood samples are taken for an hour to two hours after drinking the solution, with at least 3 blood samples taken (every 30 or 60 minutes), and each sample is promptly sent to the laboratory.

You can have the growth hormone test provided by Blazma. All you need to do is schedule an appointment, and Plasma will send a specialist to the address and time that suits you to collect the blood samples and send them to the laboratory.

How to Prepare for the Test?

A growth hormone test requires prior preparations, which we will detail below:

• Fasting: The doctor will request fasting for 10 - 12 hours before the test.
• Avoid certain medications: These include insulin, birth control pills, steroids, and St. John's wort.
• Reducing physical activity: It's essential to reduce physical activity and avoid exercising for 10 - 12 hours before the test because exercise may alter growth hormone levels.