The connection between rheumatoid arthritis (RA) and diabetes mellitus — commonly referred to as diabetes — is complex because the two conditions are risk factors for one another. In other words, having either condition (either in yourself or in your family) seems to raise a person’s chances of developing the other condition as well.
People diagnosed with RA may have up to a 50 percent higher risk of type 2 diabetes than people in the general population. Similarly, people diagnosed with type 1 diabetes may be at a higher risk of RA. A person’s risk depends on the type of diabetes they have, along with a few other factors.
There are several ways that diabetes and RA — and any inflammatory arthritis, including psoriatic arthritis — may be connected.
Type 1 diabetes occurs when the pancreas does not create enough of the hormone insulin. This hormone regulates the body’s blood sugar levels. When you don’t have enough insulin, your blood sugar level may become too high (hyperglycemia).
Type 1 diabetes is an autoimmune disease. It occurs when the body’s immune system attacks the pancreas. RA is also an autoimmune condition. It occurs when the immune system attacks the joints.
If you have been diagnosed with one autoimmune condition, you are statistically more likely than the general population to be diagnosed with another. Being diagnosed with either type 1 diabetes or RA can make it more likely that you will be diagnosed with the other, too.
Having certain genes may make it more likely that someone will be diagnosed with RA and type 1 diabetes. These genes include:
If you have had any genetic testing done, you may know whether you have one of these genes. You may also be able to request testing to determine whether you are at an increased risk of developing these conditions.
In type 2 diabetes, the body may make sufficient insulin, but it experiences insulin resistance. This means that the body does not use or interact with insulin the way it is supposed to.
Type 2 diabetes and RA are related in several ways.
Both type 2 diabetes and RA are inflammatory diseases — they are conditions that cause the body to experience an excess of inflammation.
Inflammation in RA is connected to an inflammatory protein called tumor necrosis factor, or TNF. The buildup of TNF eventually causes joint pain and other symptoms of RA.
The body produces TNF in response to an injury or infection. The protein is designed to lead the body’s immune system response by recruiting other proteins (called cytokines) to help fight infection and heal. If the body produces TNF when it doesn’t need to, however, the result is an overactive and unwarranted autoimmune response, which is seen in both RA and diabetes.
Some studies seem to show that TNF blockers — RA medications that reduce inflammation by targeting excess TNF — may slightly lower the risk of developing diabetes.
Many people who have been diagnosed with RA find it difficult to keep their bodies moving. Stiff, swollen joints can make exercise or even routine physical movement painful and challenging. Studies have shown that less-active people are more likely to develop type 2 diabetes or worsen their type 2 diabetes.
It’s important to keep exercising even after being diagnosed with RA. Rheumatologists and specialists like physiotherapists can help people with both diabetes and RA find ways to get moving without making their joint pain or other symptoms worse.
If you have been diagnosed with diabetes — particularly type 1 diabetes — but haven’t been diagnosed with RA, there are a few things you can do to monitor your condition and mitigate your risk of RA. There are also ways to continue to care for yourself if you already have both diabetes and RA.
If you notice any of the symptoms of RA in yourself, it’s time to visit your health care team to get tested for RA. The earlier you find RA, the sooner you’ll be able to find ways to manage it.
Some of the most common signs of RA include:
You may also notice problems in your lungs, eyes, skin, kidneys, salivary glands, and more. If you have any unusual symptoms, it’s reasonable to ask to be screened for RA.
Basic blood and imaging tests, like the test for C-reactive protein, can rule out RA or indicate the need for further testing. While RA can be difficult to diagnose, these basic tests can tell you and your doctor whether there is an abnormality worth exploring further.
Because diabetes and RA both involve an excess of inflammation in the body, you may want to talk to your doctor about ways to lower inflammation to decrease your chances of developing RA. In some cases, controlling inflammation may be as easy as taking nonsteroidal anti-inflammatory drugs (NSAIDs), some of which you can get over the counter.
If your inflammation is more severe, talk to your doctor about taking disease-modifying antirheumatic drugs (such as methotrexate or hydroxychloroquine) or biologics, both of which are often used to treat RA. Because these drugs also seem to have positive effects on diabetes, you and your doctor may decide that they are right for you.
Knowing that you have diabetes and RA can help your doctor choose (or avoid) certain medications that would make the other condition worse. For example, a short course of steroids could be very helpful for an RA flare-up, but it would make controlling your blood sugar more difficult. NSAIDs could be lower on the list of treatments due to their possible effects on the kidneys, a key area for diabetes complications.
One of the best ways to avoid developing RA — or to manage RA if you already have it — is to take care of your body through diet and exercise.
Aim for at least 150 minutes of exercise a week, if possible. Low-impact activities are best if you’re overweight or already dealing with RA symptoms — try water aerobics or biking. A physical therapist can help you come up with a plan if you aren’t sure where to start.
Some people recommend an anti-inflammatory diet like the Mediterranean diet for people living with RA. This diet can also be helpful for people diagnosed with diabetes. Make sure you talk to your doctor and have approval for any dietary changes you make if you are diagnosed with either type of diabetes.
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