It’s the physical examination season. Have you checked your uric acid?

Unit: Laboratory Department, Wuhan Veterans Hospital, Hubei Province Name: Fang Shengying

With the improvement of health awareness, more and more people are beginning to pay attention to physical examination indicators. In health examinations, many are basic items that must be checked, including blood routine, urine routine, liver and kidney function, blood sugar, blood lipids, thyroid function and physical examination, etc. Today we will talk about one of the kidney functions - uric acid.

When it comes to uric acid, the first thing that comes to mind is gout.

What is uric acid?

Uric acid is a metabolite of purine. In the metabolism process of old cells in the body, as well as food, especially food rich in purine (such as animal offal, seafood, etc.), the nucleic acid is oxidized and decomposed to produce purine (this endogenous purine accounts for 80% of the total purine). After purine is produced in the body, it is oxidized again in the liver to form uric acid. 2/3 of uric acid is excreted from the body with urine through the kidneys, and 1/3 is excreted through feces and sweat. It can be seen that purine is a metabolite of nucleic acid, and uric acid is a metabolite of purine.

Normal range of uric acid test

Generally speaking, normal uric acid levels are between 150-380 μmol/L for men and between 100-300 μmol/L for women. The lower the uric acid result, the better. A certain level of uric acid can fight oxidative stress, scavenge oxygen free radicals, protect the brain and nervous system, prevent the occurrence of neurodegenerative diseases, prevent cell lysis and apoptosis, protect endothelial DNA, and maintain the body's immune function. When uric acid is produced too much or excreted insufficiently, the uric acid concentration in the blood will increase. If the result is high, it indicates the presence of hyperuricemia, gout, nephritis and other diseases.

What factors may affect uric acid test results?

In addition to disease factors, many factors may affect the results of uric acid tests, including dietary effects, drug effects, and exercise effects. If you eat high-purine foods three days before the test, including animal offal, chicken breast, seafood, hot pot, etc., it may cause the uric acid test results to be high. If a large dose of vitamin C or glucocorticoids is used before the test, it may accelerate the excretion of the kidneys and increase the excretion of uric acid. If you have intense exercise before the test, the human body will metabolize a large amount of skeletal muscle adenosine triphosphate to form a large amount of endogenous purine, which will increase the uric acid content.

What happens if uric acid is high?

1. Gout: It should be noted that high uric acid does not necessarily mean gout, and gout does not necessarily mean high uric acid. High uric acid is the basis of gout. Gout is a clinical manifestation of joint redness, swelling, pain, and even dysfunction that occurs at high uric acid levels. Gout is an acute manifestation, while hyperuricemia is a continuous state. Do not assume that you have gout as soon as you see an increase in uric acid, and do not rule out gout on your own if you already have gout symptoms and find that your uric acid is not high. At this time, a professional clinical physician needs to make a comprehensive judgment.

2. Diseases with increased nucleic acid metabolism: such as leukemia, multiple myeloma, polycythemia vera, etc., in which serum uric acid levels are often elevated.

3. When renal function is impaired: normally produced uric acid is insufficiently excreted, often accompanied by increased serum uric acid.

4. Chloroform poisoning, carbon tetrachloride poisoning, lead poisoning, eclampsia, pregnancy reactions and eating foods rich in nucleic acid: can cause an increase in uric acid levels in the blood.

5. Certain drugs: such as furosemide, diuretics, tumor chemotherapy drugs, levodopa, phenytoin sodium, methyldopa, etc. can increase uric acid.

What should I do if my uric acid level rises ?

An increase in blood uric acid levels does not mean that treatment is needed immediately, and it needs to be judged based on the specific circumstances. Generally speaking, if the blood uric acid level of an adult male exceeds 420 μmol/L and that of a female exceeds 360 μmol/L, it can be considered hyperuricemia. However, not all patients with hyperuricemia require drug treatment, but rather need to be determined based on risk factors such as whether there is a history of gout attacks and whether there are cardiovascular diseases. For asymptomatic patients with hyperuricemia, it is recommended to improve lifestyle, such as reducing the intake of high-purine foods, increasing water intake, and controlling weight. If the blood uric acid level is high and there is a history of gout attacks or other risks of complications, drug intervention may be required, such as the use of uric acid-lowering drugs allopurinol and benzbromarone.