Was there a minority of people who had "gout" even with high uric acid levels?

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[Problem] "Uric acid level", which is often found in men with abnormal values ​​in the results of medical examinations. If it exceeds 7.0 mg / dL, it is called hyperuricemia, and "gout" is likely to occur. The higher the number, the higher the risk of gout. However, high uric acid levels do not mean that everyone has gout. So, at what rate does gout occur in 5 years when it exceeds 8.0 mg / dL?

(1) 10%

(2) 30%

(3) 50%

(4) 80%

The answer is on the next page

The correct answer is (2) 30%.

"Gout," which is said to "hurt even when the wind blows," is a typical illness that everyone wants to avoid. It is widely known that the cause is uric acid, but even if the uric acid level is high, there are no subjective symptoms and not all of them have gout, so many people leave it unattended. is.

In the first place, uric acid is a nitrogen compound in which three oxygen bonds to a two-ring structure called a purine ring, and most of it is excreted in urine, so it is called uric acid.

Structure of uric acid

It is well known that uric acid can be made from substances called "purines". Purine is a general term for substances that have a purine ring, and is always contained in cells. Inside a cell, there is a cell nucleus, which contains nucleic acids (DNA, RNA), which are purines with a purine ring.

Ichiro Kurume, a professor of regenerative medicine at the Graduate School of Medicine, Tottori University, who was an expert on uric acid and gout and chaired the revision of the "Guidelines for the Treatment of Hyperuricemia and Gout, 3rd Edition", said, "Many mammals. Because it can break down uric acid, it has very little uric acid, but primates, including humans, cannot break down uric acid, making it the final metabolite of purines. "

Gout risk steadily increases when uric acid levels exceed 7.0 mg / dL

The blood concentration of this uric acid is the "uric acid level". When the uric acid level in the blood exceeds 7.0 mg / dL, it is considered as a lifestyle-related disease called "hyperuricemia".

When the uric acid level exceeds 7.0 mg / dL, the uric acid crystallizes and deposits in the joints. "The physiological solubility of uric acid is 6.4 mg / dL, but due to the presence of uric acid-binding protein, it can be present in the blood up to 7.0 mg / dL without becoming supersaturated, but above 7.0 mg / dL. Then, it will not dissolve in the blood and will crystallize and deposit on the joints. "(Mr. Kurume)

When these crystals come off with some momentum, they become inflamed and cause intense pain. This is called a "gout attack". Gout often occurs below the knees, where the body temperature is low, toes and heels, and although there are individual differences in symptoms, it may be so painful that you may not be able to walk for two or three days. ..

The higher the uric acid level, the higher the risk of gout steadily. "When the uric acid level exceeds 7.0 mg / dL and rises to 8.0 mg / dL and 9.0 mg / dL, the risk of gout steadily increases," says Mr. Kurume.

Hyperuricemia when uric acid level exceeds 7.0 mg / dL

Hyperuricemia does not always cause gout

However, not all people have gout when they have hyperuricemia. It is generally said that about 10% of hyperuricemia patients have gout attacks. Yes, the majority of people do not have seizures (asymptomatic hyperuricemia). Some people do not develop the disease even if it exceeds 10 mg / dL.

The frequency of onset varies depending on the research report and race, but Mr. Kurume says, "If it exceeds 8.0 mg / dL, about 30% of people will develop gout in 5 years."

In fact, a cohort study in Taiwan found that 10.8% of people had gout attacks within 5 years at 7.0-7.9 mg / dL, 27.7% at 8.0-8.9 mg / dL, and 61.1% at 9.0 mg / dL and above. (J Rheumatol. 2000; 27: 1501-1505.).

In a 15-year cohort study in the United States, the 5-year cumulative incidence of gout was 2.0% for 7.0-7.9 mg / dL, 4.1% for 8.0-8.9 mg / dL, and 19.8 for 9.0-9.9 mg / dL. %, 30.5% above 10.0 mg / dL (Am J Med. 1987; 82: 421-426.).

Hyperuricemia is a "systemic disease" and should not be left untreated!

Looking at these data, I think that there are many people who think that the rate of developing gout is unexpectedly low, but that does not mean that hyperuricemia should be left unattended. ..

If the uric acid level rises without taking measures, not only will the risk of gout steadily increase, but the risk of various illnesses will also increase.

Mr. Kurume explains, "The risk of developing" systemic "disease due to hyperuricemia."

"Hyperuricemia is generally taken up as a risk of local joint disease from the viewpoint of gout risk, but hyperuricemia is a'systemic disease'. In recent years, lifestyles such as hypertension and diabetes There have been a series of reports pointing out the relationship between diseases, renal disorders, cardiovascular disorders, etc. The mechanism by which cells in each organ take up excess uric acid and cause organ disorders is becoming clear. " (Mr. Kurume).

Mr. Kurume says that the most typical effect is on the kidneys. "Recent studies have shown that lowering uric acid levels can protect the kidneys. In response, the December 2018 Treatment Guidelines for Hyperuricemia and Gout, Third Edition, states that kidneys can be protected. For the first time in the world, we issued a recommendation to lower uric acid levels to protect the kidneys. "(Mr. Kurume)

Unless a gout attack occurs, the uric acid level tends to be left unattended, but now that it has become clear that not only the risk of gout but also the risk of various illnesses increases, we will renew our awareness and take measures against uric acid. I would like you to work on it.

As for uric acid measures, it is important to take measures for eating habits such as eating too much, drinking too much, and refraining from foods containing a lot of purines, and measures for exercise such as aerobic exercise. Many of these also overlap with prevention of other lifestyle-related diseases and even cancer prevention measures. If you practice it, you will get double and triple benefits. Please practice it.