Gout management - don't underestimate the harm of gout

Gout is becoming more and more common. When gout attacks, it often manifests as severe pain in one or more joints. The painful area may also experience redness, swelling, fever, etc. What causes this? The key to the onset of gout lies in the level of "blood uric acid". When the concentration of uric acid in the blood exceeds its saturation in the blood or tissue fluid, sodium urate crystals are formed and deposited in the joints, inducing local inflammatory reactions and tissue destruction, resulting in inflammatory manifestations of "redness, swelling, heat and pain".

Do not underestimate the harm of gout and think that it is just a pain. If it is not controlled and treated, gout will destroy the normal morphology and function of the joints and cause inconvenience in movement. In addition, a large number of studies have shown that gout is highly correlated with the occurrence of chronic kidney disease and cardiovascular disease, and is an independent risk factor for cardiovascular disease (hypertension, coronary heart disease, etc.), diabetes and many other diseases. [1-3]

The occurrence of gout is closely related to the level of uric acid in the blood. Uric acid in the human body mainly comes from the metabolism of purine and is then excreted from the body through the kidneys. In a normal human body, the production and excretion of uric acid maintain a dynamic balance, and the blood uric acid concentration is basically below 420μmol/L, and the concentration in women is lower than that in men. Gout is a disease related to lifestyle. Generally, the factors that may lead to increased uric acid levels include: obesity, alcohol, diet, and other underlying diseases (including chronic kidney disease, hypertension, dyslipidemia, type 2 diabetes, etc.). Therefore, in order to avoid the occurrence of gout, we can pay attention to the following points in our lives [4]:

1. Control your weight and exercise regularly. Weight gain is an independent risk factor for gout, while weight loss has a protective effect. At the same time, weight loss can significantly increase the rate of uric acid control and reduce the frequency of acute gout attacks.

2. Limit the intake of alcohol, high-purine foods, and high-fructose diets. Alcohol and fructose are positively correlated with the incidence of gout. Studies have shown that heavy drinkers have a 2.64-fold increased risk of gout. Beverages and fruits rich in fructose will significantly increase blood uric acid levels. A high-purine diet will increase uric acid production in the body. Common high-purine foods include animal offal, aquatic products, etc. Patients should pay attention to appropriately reduce their consumption.

3. Encourage the intake of dairy products and fresh vegetables and drink enough water. For gout patients, the DASH diet is highly recommended, which means consuming a lot of fruits, vegetables, nuts, beans, low-fat dairy products and whole grains, and limiting the intake of sodium, sugary sweets and beverages, red meat and processed meat. Drinking enough water can promote the excretion of uric acid and prevent uric acid crystals from depositing in the body.

4. The intake of soy products (such as tofu) is neither recommended nor restricted. Because studies have shown that the purine content of soy foods varies depending on the processing method, the intake of soy products is neither recommended nor restricted.

5. Patients with other diseases should actively treat the primary disease.

After gout is diagnosed, the main treatment is to lower uric acid. The first-line uric acid-lowering drugs include allopurinol, febuxostat and benzbromarone. The first two are xanthine oxidase inhibitors that inhibit the production of uric acid in the body, while the latter inhibits the reabsorption of uric acid by the renal tubules to promote uric acid excretion. [4] Uric acid-lowering drugs should be started at a low dose, and the dose should be adjusted after 2 to 4 weeks based on the blood uric acid level and liver and kidney function. Allopurinol is effective and inexpensive, but special attention should be paid to allopurinol hypersensitivity reactions. It should not be used in patients with HLA-B*5801 positive. Febuxostat is particularly suitable for patients with chronic renal insufficiency, but its price is higher than allopurinol and it has potential cardiovascular risks. Therefore, it should be used with caution in elderly people with cardiovascular and cerebrovascular diseases, and cardiovascular events should be closely monitored. During the use of benzbromarone, because it promotes the excretion of uric acid, the uric acid level in the urine will increase. It is recommended to alkalize the urine and drink plenty of water to prevent uric acid crystallization. It is recommended to closely monitor liver function during use, and benzbromarone should be used with caution in patients with concomitant chronic liver disease.

During the acute attack of gout, anti-inflammatory and analgesic treatment is the main treatment. my country recommends colchicine or nonsteroidal anti-inflammatory drugs (NSAIDs) as first-line drugs [4]. It should be noted that colchicine interacts with many drugs. Patients using P-glycoprotein or strong CYP3A4 inhibitors (such as ketoconazole, erythromycin, clarithromycin, cyclosporine, nelfinavir, ritonavir, diltiazem, nifedipine, verapamil, etc.) and drugs metabolized by CYP3A4 (such as statins) should use colchicine with caution or use it in reduced doses. NSAIDs are preferred for fast onset and few gastrointestinal adverse reactions. They should be used with caution in the elderly, patients with renal insufficiency, and patients with a history of gastrointestinal ulcers, bleeding, or perforation. For gout patients who have been taking low-dose aspirin for a long time, it is recommended to give priority to the combination of selective COX-2 inhibitors (celecoxib) and aspirin.

Gout is a disease related to lifestyle. With the improvement of living standards, people's lifestyles have changed, and the incidence of gout has become increasingly higher. It has become another common metabolic disease after diabetes. Similar to diabetes and hypertension, most patients need lifelong uric acid-lowering drug treatment. Patients must pay attention to it, control uric acid levels, and prevent attacks and progression.

【References】

[1]. Wu, J., et al., Hyperuricemia and clustering of cardiovascular risk factors in the Chinese adult population. Scientific Reports, 2017. 7(1).

[2]. Bardin, T. and P. Richette, Impact of comorbidities on gout and hyperuricaemia: an update on prevalence and treatment options. BMC Medicine, 2017. 15(1).

[3]. Sato, Y., et al., The case for uric acid-lowering treatment in patients with hyperuricaemia and CKD. Nature Reviews Nephrology, 2019. 15(Suppl. 3).

[4]. Chinese Guidelines for the Diagnosis and Treatment of Hyperuricemia and Gout (2019). Chinese Journal of Endocrinology and Metabolism, 2020(01): pp. 1-2-3-4-5-6-7-8-9-10-11-12-13.