Growth hormone suppression test

At least three blood samples are taken. The test is done in the following way: The first blood sample is collected between 6 a.m. and 8 a.m. before you eat or drink anything. You then drink a solution containing glucose (sugar). You may be told to drink slowly to avoid becoming nauseated. But you must drink the…

Do not eat anything and limit physical activity for 10 to 12 hours before the test. You may also be told to stop taking medicines that can affect the test results. These medicines include glucocorticoids such as prednisone, hydrocortisone, or dexamethasone. Check with your health care provider before stopping any…

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

This test checks to see if a high level of GH can be suppressed by taking a glucose load. If it cannot, this may lead to gigantism in children and acromegaly in adults. It is not used as a routine screening test. This test is only done if you show signs of increased GH.

Normal test results show a GH level of less than 1 ng/mL. In children, GH level may be increased due to reactive hypoglycemia . Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific…

If the GH level is not changed and stays high during the suppression test, your provider will suspect gigantism or acromegaly. You may need to be retested to confirm the test results.

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others. Risks of having blood drawn are slight, but may include: Excessive bleeding Multiple…

Kaiser U, Ho K. Pituitary physiology and diagnostic evaluation. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 8. Melmed S. Acromegaly. In: Robertson RP, ed. DeGroot's Endocrinology . 8th ed. Philadelphia, PA: Elsevier;…