What is the normal value of urine amylase?

The human body has an excretion system, and what is excreted every day is the filtered sediment. This is metabolism. However, in addition to producing some diet or other elements, the human body also produces urinary amylase. This product will be absorbed into the human blood, filtered and purified in the blood, and finally excreted through urine. In the examination of certain diseases, the detection of urinary amylase will be mentioned, and such examination is mainly to help diagnose pancreatic diseases as soon as possible.

Clinical significance

Serum and urine amylase are secreted from the pancreas and salivary glands. Under normal circumstances, most amylase enters the digestive tract with digestive juices, and a small amount can enter the blood circulation. There are three reasons for increased serum amylase activity:

Inflammatory damage to pancreatic tissue increases enzyme release; excessive secretion; and excretion of pancreatic and other tissues is blocked. Since amylase has a small molecular weight, it is easily excreted from the urine through the glomerulus, so increased serum amylase activity is also reflected in the urine. Therefore, blood and urine amylase tests are mainly used to diagnose pancreatitis.

In chronic pancreatitis, serum amylase activity increases, but the degree of increase is lower than that in acute pancreatitis. In addition, diseases such as acute peritonitis, intestinal obstruction, liver disease, renal insufficiency, and acute mumps can cause a slight increase in serum amylase activity. Generally, a level greater than 300 Soxhlet units is an important basis for diagnosing acute pancreatitis. In acute pancreatitis, amylase in urine begins to increase 12 to 24 hours after the onset of the disease. It is generally believed that the frequency and degree of increase in urinary amylase are higher than those of serum amylase, and after the serum amylase activity returns to normal, the increase in urinary amylase activity may still persist for 5 to 7 days. Therefore, urinary amylase activity measurement is very valuable for the diagnosis of acute pancreatitis, especially for patients who do not seek medical treatment in time.

Acute pancreatitis: Generally, serum amylase increases 2 to 12 hours after the onset of clinical symptoms, reaches a peak in 12 to 24 hours, and returns to normal in 2 to 4 days. Therefore, serum amylase activity determination is a better method for diagnosing acute pancreatitis. Since the increase in serum amylase activity in acute pancreatitis is transient, blood tests should be drawn in time if acute pancreatitis is suspected, otherwise false negative results are likely to be obtained. The increase in serum amylase activity lasts longer when there are complications or relapses.

Normal values ​​of urine amylase

Health value: Somogyi method: 80~300U/L; Folgmuth method: 16~64U/L; Winslow method: 8~32U/L

Examination introduction: serum pancreatic amylase P-AMY [reference value] <115U/L urine amylase UAMY [reference value] 100--330U/L

There are many normal values ​​for urinary amylase, normal 0-1200U/L, and normal urinary amylase is 80-300 Soro units/hour. More than 300 units/hour has diagnostic value. There is also a normal value: <1000u/l.

Expert interpretation

1. Increase is seen in: Acute pancreatitis generally begins to increase 12 hours after onset. >1000U/L can be diagnosed as acute pancreatitis. It takes 3 to 10 days to return to normal, and the duration is slightly longer than that in the blood, 5 to 7 days. Moderately elevated levels occur during acute attacks of chronic pancreatitis; dehydration, shock, secondary renal dysfunction, pancreatic cancer, pancreatic trauma, common bile duct obstruction, cholelithiasis, gastric ulcer perforation, mumps, alcohol poisoning, etc.

2. Reduction is seen in severe hepatitis, cirrhosis, cholecystitis, diabetes, severe burns, thyrotoxicosis, etc.

Pathology of urinary amylase: Pathological increase: It is more common in acute pancreatitis, pancreatic duct obstruction, pancreatic cancer, pancreatic injury, acute cholecystitis, gastric ulcer, mumps, etc. In the above diseases, the patient's serum amylase and urinary amylase are often increased at the same time; Pathological decrease: It is mainly seen in severe hepatitis, cirrhosis, diabetes, etc.; In macroamylasemia, urinary amylase is normal, but serum amylase is significantly increased.