Chronic inflammation associated with rheumatoid arthritis can damage the kidneys and may increase the risk of kidney disease.
People with rheumatoid arthritis (RA) have chronic inflammation. This inflammation can affect the kidneys.
Medications for RA are typically safe for the kidneys. However, in people with preexisting kidney problems, they may increase the risk of kidney disease.
This article examines the link between RA and kidney disease, signs to look out for, and ways people with RA can help protect their kidneys.
RA is an inflammatory disease that affects the joints and organs in the body. People with RA have chronic inflammation that causes joint pain, which is the main symptom of RA. This inflammation can also affect other areas, including the kidneys.
Around 1 in 4 people with RA may develop chronic kidney disease (CKD).
Inflammation from RA can cause kidney damage in the following ways:
Chronic inflammation can damage the lining of blood vessels and cause plaque buildup. This can occur in blood vessels throughout the body, including the kidneys.
Plaque can reduce blood flow to the kidneys, limiting the amount of oxygen and nutrients they receive. This can lead to reduced kidney function and may progress to kidney disease.
Unmanaged RA may also lead to amyloidosis. Amyloidosis is a buildup of the protein amyloid in the kidneys, which can lead to reduced kidney function.
People with RA have an increased risk of glomerulonephritis. Glomeruli exist in the kidneys help to filter waste products from the blood. RA can cause inflammation of the glomeruli, known as glomerulonephritis, which can negatively affect kidney function and may cause CKD.
RA may increase the risk of cardiovascular problems, including high blood pressure. Unmanaged high blood pressure can cause damage to blood vessels in the kidneys over time, which makes the kidneys less able to remove waste and excess fluid from the body.
Fluid buildup in the blood vessels can increase blood pressure further, leading to a cycle of high blood pressure and reduced kidney function.
Learn about the link between high blood pressure and kidney disease.
Medications for RA may also impair kidney function in people with existing kidney problems. The kidneys may not be able to filter medication out of the bloodstream effectively, leading to further kidney damage.
The two main risks for kidney disease in people with RA are:
People with RA may have elevated inflammatory markers. These can increase the risk of developing CKD.
Chronic inflammation can play a role in kidney dysfunction. Inflammation can affect blood vessels, including the small vessels in the kidneys. More severe RA may increase the risk of kidney disease.
Drug-induced kidney disease
Medications to treat RA may not directly harm the kidneys. However, they may affect kidney function if a person already has kidney problems. Medications include:
- nonsteroidal anti-inflammatory drugs (NSAIDs), which can reduce blood flow to the kidneys
- corticosteroids, which can contribute to kidney disease through high blood pressure over time
- methotrexate, which may build up in the bloodstream and cause an overdose if the kidneys do not function effectively
- cyclosporine, which may reduce kidney function while people are taking the drug
Other risk factors
Other risk factors for kidney disease include:
- having diabetes
- having heart disease
- having high cholesterol
- having high blood pressure
- being African American
- having a family history of kidney disease
People may not have signs of kidney disease in the early stages. As the disease progresses, people may notice the following symptoms:
- loss of appetite
- nausea or vomiting
- fatigue and weakness
- swelling in the lower body, including the legs, ankles, and feet
- changes in urination, such as increased urination
- difficulty concentrating
- persistent itching and rashes
- puffy eyes
- muscle cramps or twitching, particularly at night
- difficulty sleeping
- chest pain, which can indicate a fluid buildup around the heart lining
- shortness of breath from a fluid buildup around the lungs
- high blood pressure
There are no specific recommendations for people with RA to undergo testing for kidney disease.
People may want to talk with a healthcare professional about getting regular kidney function tests, which include blood and urine tests.
Getting tests for other risk factors, such as high blood pressure, may also help to reduce kidney disease risk. Experts recommend trying to maintain a blood pressure of 120/80.
People with RA can take the following steps to protect the kidneys:
- Manage RA: Effectively managing RA can help manage inflammation, which can help protect the kidneys. This can involve taking medication exactly as a doctor prescribes and keeping track of symptoms.
- Discuss medication side effects with a doctor: People with kidney problems and RA can talk with a doctor about their RA medications and ask whether a lower dose is possible. People with reduced kidney function may also need to avoid NSAIDs.
- Get regular testing: People can talk with a doctor about getting regular blood and urine tests to check how well their kidneys work.
- Manage blood pressure and cholesterol: High blood pressure and cholesterol can increase the risk of kidney disease. Getting regular blood pressure and cholesterol checks and making certain lifestyle choices may help. For example, a person may wish to avoid certain foods and choose others.
- Drink plenty of fluids: Staying well hydrated and drinking plenty of water can help support kidney function.
- Limit salt intake: Excess salt can increase blood pressure, which can increase the risk of kidney problems.
People with RA may have an increased risk of kidney disease. The chronic inflammation associated with RA can damage blood vessels in the kidneys, leading to reduced kidney function. In people with kidney problems, medications for RA may also worsen kidney function.
Managing RA and inflammation is important for protecting the kidneys. People with RA can also protect the kidneys by getting regular kidney function tests, taking steps to look after their cardiovascular health, drinking plenty of water, and taking medications exactly as a doctor prescribes.
People can talk with a doctor about medication side effects and possible dosage adjustments.