Vasoactive intestinal polypeptide test
Vasoactive intestinal peptide (VIP) is a test that measures the amount of VIP in the blood.
How to Prepare for the Test
You should not eat or drink anything for 4 hours before the test.
How the Test will Feel
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 a slight bruise. This soon goes away.
Why the Test is Performed
This test is used to measure VIP level in the blood. A very high level is usually caused by a VIPoma. This is an extremely rare tumor that releases VIP.
VIP is a substance found in cells throughout the body. The highest levels are normally found in cells in the nervous system and gut. VIP has many functions, including relaxing certain muscles, triggering release of hormones from the pancreas, gut, and hypothalamus, and increasing the amount of water and electrolytes secreted from the pancreas and gut.
VIPomas produce and release VIP into the blood. This blood test checks the amount of VIP in the blood to see if a person has a VIPoma.
Normal values range from less than 75 to 190 pg/mL.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
A higher-than-normal level, along with symptoms of watery diarrhea and flushing, may be a sign of a VIPoma.
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Dickson PV, Behrman SW. Management of pancreatic neuroendocrine tumors. Surg Clin N Am. 2013;93:675-91.
Salwen MJ, Siddiqi HA, Gress FG, Bowne WB. Laboratory diagnosis of gastrointestinal and pancreatic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 22.