What is the use of gastrin test

Gastrin examination is mainly used to assist in the diagnosis of gastrinoma, evaluate gastric acid related diseases, and monitor the recovery of certain gastric surgery patients. Gastrin is a hormone secreted by G cells in the gastric antrum, whose main function is to stimulate gastric acid secretion. Therefore, by detecting the level of gastrin in the blood, the status of gastric acid secretion and related diseases can be indirectly understood.

1. Diagnosis of gastrinoma:

Gastrinoma is a neuroendocrine tumor that can cause abnormal secretion of gastrin, leading to refractory, multiple peptic ulcers and diarrhea. When patients experience recurrent gastric or duodenal ulcers, especially when the ulcer location is atypical or conventional treatment is ineffective, doctors will recommend a gastrin test. If the fasting serum gastrin level significantly increases, usually several times higher than the upper limit of normal, combined with gastric acid analysis or stimulation test, it can be highly suspected of gastrinoma. After diagnosis, further imaging examinations such as CT or endoscopic ultrasound are needed to locate the tumor in order to develop surgical or drug treatment plans.

2. Evaluation of chronic atrophic gastritis:

Patients with chronic atrophic gastritis have gastric mucosal atrophy and reduced gastric acid secretion, which can lead to an increase in gastrin levels through a negative feedback mechanism. Therefore, gastrin testing is often combined with pepsinogen testing as a non-invasive screening indicator for gastric mucosal atrophy. If the level of gastrin significantly increases and the ratio of pepsinogen I/II decreases, it suggests that there may be atrophic changes in the gastric body or fundus. These patients need regular follow-up because long-term atrophic gastritis carries a risk of progressing to gastric cancer. The doctor will recommend whether the patient needs to undergo gastroscopy and pathological biopsy based on the examination results to clarify the diagnosis and guide subsequent treatment.

3. Monitoring the postoperative status of gastric surgery:

Some patients may undergo subtotal gastrectomy or vagotomy due to peptic ulcer or gastric cancer, and their gastric acid secretion function may change after surgery. Gastrin test can be used to evaluate surgical outcomes and monitor the risk of recurrence. For example, after gastric antrectomy, serum gastrin levels usually decrease due to the removal of G cells that secrete gastrin; If the postoperative gastrin level continues to abnormally increase, it is necessary to be alert to the possibility of residual gastric cancer or gastrinoma recurrence. In addition, for obese patients undergoing gastric bypass surgery, changes in gastrin levels can also help evaluate the impact of surgery on gastrointestinal hormone regulation, thereby guiding postoperative nutritional management and prevention of complications.

4. Auxiliary diagnosis of high gastric acid secretion status:

In addition to gastrinoma, other diseases that cause excessive gastric acid secretion can also cause changes in gastrin levels, such as Zollinger Ellison syndrome and systemic mastocytosis. When patients experience severe acid reflux, heartburn, upper abdominal pain, or esophageal reflux symptoms, and conventional acid suppression therapy is ineffective, gastrin testing can help identify whether there is a state of high gastric acid secretion. If the level of gastrin increases, further exclusion of gastrinoma is necessary; If the level of gastrin is normal or low, but the secretion of gastric acid is still excessive, it may be caused by other reasons. Doctors will combine the patient's clinical symptoms, gastroscopy results, and stomach acid testing to comprehensively determine the cause and develop personalized acid suppression treatment plans.

5. Evaluation of gastrointestinal endocrine function:

Gastrin levels can also reflect the functional status of gastrointestinal endocrine cells. Some autoimmune diseases, such as autoimmune gastritis, can cause damage or dysfunction of gastric mucosal G cells, leading to disrupted secretion of gastrin. In addition, patients who use proton pump inhibitors for a long time may experience compensatory elevation of gastrin levels through negative feedback due to strong suppression of gastric acid. Gastrin test can be used to evaluate whether the gastrointestinal endocrine regulation of such patients is within the normal range, helping doctors determine whether it is necessary to adjust the dosage or course of acid suppressive drugs. For individuals with a family history of gastrointestinal neuroendocrine tumors, regular monitoring of gastrin levels can also help detect potential endocrine abnormalities early.

Gastrin test is an important tool in the diagnosis of digestive system diseases, but a single abnormal result cannot directly confirm the diagnosis. It needs to be comprehensively judged based on the patient's symptoms, endoscopic and imaging examinations. Regular diet should be maintained in daily life, avoiding long-term fasting or overeating, reducing high-fat and spicy food stimulation, quitting smoking and limiting alcohol consumption. If you experience recurrent abdominal pain, acid reflux, diarrhea, or unexplained weight loss, it is recommended to seek medical attention promptly at the gastroenterology department. A doctor should evaluate whether gastrin and related tests are necessary, and do not interpret the results or blindly use medication.