This test measures the amount of gastrin in your blood. Gastrin is a hormone made by G cells in the lower part of your stomach. It controls the release of gastric acid by other cells in the stomach when you eat. You need gastric acid to break down your food, but too much gastric acid can cause stomach problems.
If you have recurrent peptic ulcers, you may have this test to determine whether you also have Zollinger-Ellison (ZE) syndrome, G-cell hyperplasia, or another condition. If you have ZE syndrome, you may have tumors called gastrinomas in your pancreas and the first part of your small intestines. These tumors can be cancerous.
In G-cell hyperplasia, the G cells in your stomach lining make too much gastrin.
If you are being treated for peptic ulcer disease, you may have this test to see if your treatment is effective.
You may also have a gastric acid level, or pH, test to measure the acid in your stomach juices or tests that stimulate gastrin production.
Many things may affect your lab test results. These include the method each lab uses to do the test. Some laboratories may have slightly different normal values than the ones below. Even if your test results are different from the normal values, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
The results are expressed in picograms per milliliter of blood (pg/mL). The normal range is:
0 to 180 pg/mL for adults
0 to 125 pg/mL for children
Your levels may be higher if you are an older adult.
Patients with ZE syndrome or G-cell hyperplasia usually have levels of gastrin in their blood that are quite high. But you could have ZE syndrome without high levels of blood gastrin. Other conditions and some medicines can also raise gastrin levels.
The test requires a blood sample, which is drawn through a needle from a vein in your arm.
Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.
Things that may affect your test results include:
Having peptic ulcer surgery
Eating a lot of high-protein foods
Taking insulin to treat diabetes
Taking antacids or other drugs that block gastric acid production
Taking calcium supplements
Taking antidepressants, which can lower your gastrin levels
You must fast for 12 hours before the test. (You can drink water.) Do not drink alcohol for at least 24 hours before having this test. Be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.