Gout is a painful form of inflammatory arthritis caused by a build-up of uric acid (urate), a waste product produced when the body breaks down purines, a chemical compound found in food but also made in the body.
One in 10 people with kidney disease have gout, and about 1 in 4 people with gout have CKD.
“Uric acid crystals accumulate in the soft tissue and joints, causing painful attacks of inflammation. If left untreated, these crystals can develop into tophi – hard lumps of uric acid crystals which form under the skin often near joints and cause joint damage,” explains Dr Kelsey Jordan, consultant rheumatologist at University Hospitals Sussex NHS Trust, and a trustee of the UK Gout Society.
“Crystals can also accumulate in the renal tract, resulting in kidney stones.”
People with CKD are more prone to gout as their kidneys aren’t working as well, so they can’t filter the waste product uric acid from the blood and excrete it in urine as efficiently as healthy kidneys. Up to 25 per cent of people with CKD stage 3 to 5 are likely to develop gout because of high urate levels in their body.Dr Kelsey Jordan, consultant rheumatologist at University Hospitals Sussex NHS Trust
What causes gout?
Gout is caused by having too much uric acid in your blood.
“All of that Henry VIII-th-style-diet-causes-gout stuff is absolute nonsense and has nothing to do with why people get gout,” says Dr Jordan.
“You get gout because your kidneys are not filtering out the urate efficiently and the only successful way to manage that long term is with effective drug treatment.”
Approximately 75 per cent of purines are made in the body, confirms kidney dietitian Ravinder Sagoo, founder of Kidney Nutrition Matters. Only 25 per cent come from our diet and the fluids we drink.
“Purines don’t cause gout, but they might trigger an attack,” she explains.
What are the symptoms of gout?
Gout attack or flare up pain has been ranked as similar to heart attacks or broken bones by some sufferers – it really hurts.
- Symptoms include sudden, severe pains in joints, most commonly the big toe, but any joint can be affected including feet, ankles, knees, and upper limb joints.
- The skin covering the inflamed area may look red and shiny (less so on darker skins) and may be so inflamed that it peels.
- A flare up or attack can last around a week if not treated.
"People with CKD often have other chronic health conditions such as heart disease and diabetes, so doctors don’t always think of gout as a significant part of their overall health as they have lots of other things going on,” says Dr Jordan.
"But patients say gout is such an incredibly painful condition that they do want treated. Sadly, it's often something that is slightly ignored, or there’s a myth that patients can’t have treatment because their kidneys are so impaired that treatment is not suitable for them.”
Dr Jordan says the longer high urate levels go untreated, the more crystals will accumulate around joints and soft tissues, potentially causing irreversible damage to the joints.
"People often don’t understand that uric acid crystals build up if you don’t take medication to lower your levels all the time. Taking tablets just when you have an attack isn’t enough.
"If we can catch gout early and reduce uric acids levels, joint damage can be prevented and gout can be cured.”
How are gout attacks treated?
Gout attacks in people without CKD are normally treated with non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen. However, NSAIDs are rarely suitable for you if you have CKD as they can affect your kidney function, says Pooja Gudka, senior specialist renal pharmacist at the Royal Free London NHS Foundation Trust.
“Certainly, in the later stages of CKD (stages 3 to 5) taking NSAIDs should be avoided. In the early stages of CKD your GP, nephrologist, or rheumatologist may say short-term use of NSAIDs is fine, but always check with them first,” says Pooja.
“As an alternative your GP can prescribe colchicine, which is used to treat and prevent gout attacks. It works by reducing inflammation caused by the crystals of uric acid that build up in your joints.”
Colchicine takes between 30 minutes and two hours to start working, but it may take a day or two to bring pain under control.
“It’s normally okay to take colchicine for all stages of kidney disease, but in the later stages the dose needs to be reduced and given for longer as it can cause diarrhoea, which can lead to dehydration and worsen kidney disease,” says Pooja.
A third option is a short course of the steroid prednisolone, which can be used at any stage of kidney disease. “However, the side effects can cause weight gain, changes in mood and sugar levels, so it’s a shorter-term treatment for gout attacks, and shouldn’t be used for extended periods,” says Pooja.
Acute gout treatments do not lower urate levels and are for acute management during an attack.
Treatments to help prevent gout
To prevent attacks and damage from occurring, long-term treatment needs to be given with urate-lowering drugs. These reduce urate levels in the blood and urine to reduce and eventually clear deposited crystals from joints and soft tissues, dissolve tophi and prevent joint damage.
"To accomplish this, the urate needs to be suppressed below 0.36mmol/L forever. This is known as ‘treat to target’,” says Dr Jordan.
"When gout is first treated, especially if the urate is high, which is often the case in CKD patients, there is a risk of inducing gout attacks as the deposited crystals are mobilised and dissolved.”
Some doctors suggest patients are treated with a small prophylactic (preventative) dose of colchicine for 3 to 6 months to try and prevent attacks during this period and until the urate levels have been stable for several months, Dr Jordan explains.
Allopurinol is the first line treatment for gout and works by reducing uric acid production by inhibiting an enzyme called xanthine oxidase.
"A lot of people worry that people with CKD can’t have high doses, but with our experience in kidney clinics, we know that CKD patients can tolerate maximum doses of up to 300mg daily if it is started at 100mg and gradually increased,” says Pooja. "My motto is start low, go slow.”
Febuxostat is an alternative to allopurinol, which works in a similar way, but can be more potent than allopurinol and therefore increases the risk of flares when starting treatment.
These include benzbromarone and probenecid, which work by pushing the urate out through the kidney but can increase the risk of kidney stones in some patients.
Rasburicase is given by IV drip and mainly used to prevent renal failure in cancer patients.
Healthy diet choices if you have gout and CKD
Ravinder does not recommend following any specific diet to stop flare ups. “There’s an association between cherry juice and a reduced risk of gout, but not enough evidence to endorse it.”
Try to eliminate highly processed foods and drinks and increase your fruit and vegetable intake, checking with your kidney dietitian about the most appropriate choices for you if you also have gout.
Cut down on sweetened foods
"Foods and beverages sweetened with glucose, fructose syrup or corn syrup, as well as sweetened soft drinks, increase the risk of gout,” says Ravinder.
Make kidney- and gout-friendly protein choices
"Eat moderate amounts of meat, fish and alternatives, avoiding eating large portions,” says Ravinder. "Protein still remains a very important part of the diet and there are some good sources that are both kidney- and gout-friendly including cottage cheese, chicken breast, cod fillet, eggs, hard cheese and almonds.”
"You should also include moderate amounts of low-fat dairy products – the recommended amount is three portions of dairy products daily, for example a 200ml glass of milk, a pot of yoghurt and a matchbox-sized piece of hard cheese.
"Discuss options with your kidney dietitian if you are limiting phosphate intake.”
Choose low purine foods
Purines break down in the body and produce uric acid.
"Although foods high in purines don’t cause gout, they may make flare ups more likely, so it makes sense to moderate your intake,” says Ravinder.
"There are low purine vegetables and fruits, but some low purine items also have a high potassium level and so may need limiting if you have CKD,” explains Ravinder. Be aware that even low purine foods may trigger a reaction in some people. “It’s best to avoid these foods if you have had a bad experience,” she advises.
| High purine foods | Medium purine foods | Low purine foods |
|---|---|---|
| • Offal: liver and kidneys heart and sweetbreads | • Beef, lamb, chicken, pork, and duck | • Low-fat dairy foods: milk, cheese yogurt and butter |
| • Game meat: pheasant, rabbit, and venison | • Dried peas, beans, legumes, mushrooms | • Eggs, bread, and cereals (except wholegrain) |
| • Oily fish: anchovies, herring, mackerel, sardines, sprats, whitebait, and trout | • Some vegetables including asparagus, cauliflower, and spinach | • Pasta, noodles |
| • Seafood: mussels, crab, shrimps, and other shellfish, fish roe and caviar | • Wholegrains: oat bran, bran and wholemeal bread | • Low purine fruits such as strawberries, oranges |
| • Meat and yeast extracts: Marmite, Bovril, some gravy powders, and beer | • Quorn products | • Low purine vegetables such as tomatoes |
Why advice from a dietitian is vital
Seeking advice from your kidney dietitian will ensure you make choices based on your nutritional requirements and food preferences, keeping blood test results in mind.
“For example, as a kidney patient you would be encouraged to eat oily fish, which contains omega 3 fats, because of their well-researched benefits. However, if you have CKD and gout, oily fish would be discouraged, as well as some specific vegetables and fruit.”
"It can be tricky to juggle all this, as well as limiting potassium and phosphates in some cases,” says Ravinder.
Fluids, gout and CKD
If you have gout you’ll be advised to drink plenty of water (2 litres a day).
If you also have advanced CKD, or have had a kidney transplant, the advice will be different; for example, you may be on a fluid restriction.
Always consult your kidney team and rheumatologist for personalised advice about how much you should be drinking.
Does alcohol cause gout and trigger attacks?
Alcohol can increase your chances of developing gout and of triggering an attack, according to the UK Gout Society.
Research from Boston University School of Medicine has found that all types of alcohol, even in moderate amounts, are associated with an increased risk of recurrent gout attacks in people with untreated gout.
Ravinder says it’s not necessary to give up alcohol completely, but important to stay within safe limits of no more than 14 alcohol units a week, learn what quantities trigger a flare up within those safe limits and have two to three alcohol-free days a week.