Gout and Kidney Disease

What is gout? How is it caused?

Gout happens when uric acid, a normal body waste, gets too high in the blood. Uric acid comes from the breakdown of purines, which are chemicals found in both our diet and our bodies. In some people, high uric acid may turn into crystals that settle in the joints.

These crystals may cause pain and swelling that limit how you move. They may also change the shape of your joints over time.

Some people with very bad gout get tophi, which are lumps of uric acid under the skin. They usually form on the joints, fingers, and the upper ear.

What are the risk factors for gout?

Many things can increase the level of uric acid in the body, including certain foods, other diseases, or certain medicines. Being dehydrated (having too little water) can also increase the concentration of uric acid in the blood. Other possible risk factors can include obesity, age, and family history of gout.

How are gout, uric acid, and kidney disease connected?

Uric acid moves through your blood to your kidneys. Your kidneys then add that uric acid to your urine, so it can leave the body. However, sometimes uric acid in the blood gets too high. This happens because: the body makes too much uric acid, and/or the kidneys can’t add enough uric acid to your urine, so it builds up in your blood (the more common reason). That’s why having gout and high uric acid may be signs of kidney disease, so if you have gout, get checked for kidney disease.

If you already know you have kidney disease, ask your healthcare professional about gout. Some studies show that gout and high uric acid may harm the kidneys. It’s very important to treat your gout early to protect your kidneys from more harm.

High uric acid may not cause problems for many people, but it may cause gout in some people.

What are some signs and symptoms of gout?

  • Swelling
  • Tenderness
  • Stiffness
  • Redness

More than half of patients get their first gout attack in a big toe (called podagra), and most patients will get it there at some point during the disease.

What can happen if gout gets worse? What are the complications?

If gout isn’t treated, it can become a long-term problem and affect many joints at once, in both the lower and upper body. At this stage, joints can be damaged, and pain is constant. Tophi can also form in many other parts of the body.

Uric acid crystals can form kidney stones in some people. These stones are very painful and can hurt the kidneys by:

  1. blocking the kidneys from removing wastes, which can cause infection, and
  2. scarring the kidneys with their sharp edges. Both problems can lead to CKD, and even kidney failure.

What is refractory gout?

Refractory gout is a rare form of severe gout. Both gout and refractory gout are very painful, but refractory gout more often leads to serious problems like permanent joint damage and trouble with moving and walking. Refractory gout may not go away with standard treatments. Other medicines may be needed. People with either gout or refractory gout can also have problems with their kidneys.

With refractory gout, uric acid levels remain high with standard treatment and symptoms (including painful and swollen joints) become chronic, which means long-term or permanent.

Along with the symptoms listed above, these problems can also happen:

  • Chronic arthritis
  • Lumps or nodules on the hands, elbows, or other parts of the body. These are caused by hard uric acid deposits under the skin known as tophi, which can be painful and disfiguring.

How is gout tested and diagnosed?

A physical exam will check for signs and symptoms related to gout. Medical and family history will also be reviewed. The levels of uric acid will be checked in the blood and urine. Fluid from an affected joint might also be examined for gout crystals. Test for gout can include the following:

  • Arthrocentesis, also called synovial fluid aspiration of the joint: A needle is used to take fluid from a joint to see if it has uric acid crystals. The fluid is studied under a microscope to find crystals. This method is the gold standard for diagnosing gout.
  • Imaging: Ultrasound, CT scan, and magnetic resonance imaging (MRI), have also been used for diagnosing gout.
  • Uric acid level: The blood test for uric acid is called serum uric acid (sUA) and the normal range depends on your age, gender, and each lab’s normal values. Most experts say that if you have gout, your uric acid level should stay below 6.0 mg/dL to prevent gout attacks. Some people may need to keep their uric acid level lower than 6.0 mg/dL.

How is kidney disease tested?

Kidney disease is diagnosed with two simple tests:

  1. Glomerular filtration rate (GFR): a blood test that checks how well the kidneys are filtering wastes from your blood.
  2. Albumin-to-creatinine ratio (ACR): a urine test that shows if protein (albumin) levels are too high, which may mean kidney damage.

What are some treatments for gout?

Gout can be managed with dietary changes, medicine, and management of other conditions that raise uric acid levels.

Medicines

Sudden gout flares: non-steroidal inflammatory drugs (NSAIDs) like ibuprofen and naproxen are pills usually avoided in CKD. The pill colchicine is often used, but the dose is lowered for people with CKD. Cortisone is sometimes used in CKD, and can be given as a pill or a shot.

Long-term treatment to lower uric acid and prevent gout flares: allopurinol, febuxostat, probenecid, and lesinurad are all pills. Pegloticase is given through a vein for severe gout that doesn’t get better with pills. When you start long-term therapy, you’ll also take one of these medicines for a while to prevent gout flares: colchicine; an NSAID if it’s safe for you; or cortisone.

Lifestyle changes

Avoid or limit high purine foods and drinks like organ meats, shellfish, beer, and products with high-fructose corn syrup. Eating less animal protein like meat keeps the urine less acid, which may lower the risk for gout flares and kidney stones. Eat lots of vegetables and fruits.

Drink plenty of water, unless your healthcare professional says you need to restrict your fluid intake. Drink water at night too, when crystals tend to form more often.

Treat kidney disease, obesity, high blood pressure, high blood sugar, and heart disease, because they may increase uric acid and the risk for gout. Review all medicines and supplements with your healthcare professional, as some can increase uric acid.

What about supplements, or herbal / alternative medicines for gout?

Before taking any medicine or supplement, speak with your doctor, pharmacist or other member of your healthcare team to make sure they won’t hurt your kidneys.

Certain herbal medicines may have ingredients that can harm the kidneys or make kidney disease worse. They can also interact with prescription medicines to either increase or decrease how well the medicine works.

How can I protect my kidneys and lower my risk for gout flares?

  • Eat healthy. Be aware of portion sizes and don’t skip meals.
  • Be more active.
  • Control high blood pressure and high blood sugar.
  • Lose weight if needed. Extra weight can lead to high blood pressure and diabetes, which can hurt the kidneys.
  • Avoid NSAIDs such as ibuprofen and naproxen, which can hurt the kidneys.
  • Don’t take herbal supplements. Many herbal products can harm the kidneys.
  • Don’t smoke. Smoking increases the chance of heart and lung disease, and stroke.
  • If you need a test such as an MRI with contrast dye, make sure your doctor measures your kidney function first.
  • Know your eGFR and UACR test results.

How can I track my labs and gout flares?

You can speak to your healthcare team about access to your lab results (printout or online access, depending on the practice). You may also be able to directly access your lab tests straight from the lab.

You can also track your serum uric acid (sUA) level (amount of uric acid in your blood), estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio using the online Gout and Uric Acid Tracker by clicking here (Excel download), or by printing out the PDF version.