If you’re living with systemic lupus erythematosus (SLE), you already know it can affect any part of your body. So, if you’re having trouble regulating your glucose (blood sugar) levels, you may wonder whether lupus could be playing a role.

Problems with blood sugar are usually linked to diabetes, a chronic (long-term) condition that causes hyperglycemia (high blood sugar). But even people without diabetes can experience blood sugar that’s too high or too low (hypoglycemia).

If you have lupus, both your condition and its treatment can affect your blood sugar levels. Understanding the connection between lupus and blood sugar can help you spot changes early — and work with your healthcare team to stay healthy and balanced.

Understanding How Your Body Regulates Blood Sugar

To understand how lupus can affect blood sugar levels, it helps to learn more about how your body keeps blood sugar levels steady.

Glucose is your body’s main source of energy. Most of the glucose in your blood comes from carbohydrates (carbs) in the food and drinks you consume. During digestion, carbs are broken down into glucose, which then enters your bloodstream.

Your pancreas is responsible for managing how your body uses glucose. It produces a hormone called insulin in response to rising blood glucose levels. Insulin helps your body’s cells absorb glucose and use it for energy. When your blood glucose levels are high, insulin binds to insulin receptors on your cells, signaling them to take in glucose from the bloodstream. In general, when your insulin levels go up, your blood glucose levels go down.

Your body works hard to regulate your blood sugar and keep it at a healthy level. After you haven’t eaten for a few hours, your blood glucose levels fall and your pancreas stops releasing insulin. If your blood sugar levels drop too low, your pancreas will release another hormone called glucagon. This hormone tells your liver to release stored glucose back into your bloodstream. In certain situations, your kidneys and liver can also make glucose from stored fat.

Problems with regulating blood sugar are most commonly associated with diabetes. People with diabetes either don’t make enough insulin (type 1 diabetes) or their bodies become less responsive to it (type 2 diabetes).

Lupus and Hypoglycemia

For people without diabetes, hypoglycemia means having a blood glucose level below 55 milligrams per deciliter (mg/dL). People with diabetes may begin to notice signs and symptoms of hypoglycemia when their blood glucose drops below 70 mg/dL.

However, you probably won’t learn from a blood test that your sugar level has dipped — sudden symptoms like dizziness or shakiness are more likely to alert you that something’s wrong.

Hypoglycemia is most common in people with diabetes who use insulin or medications to manage their insulin levels. Synthetic insulin and medications that increase the hormone are often used to treat diabetes. If a person with diabetes ends up with too much insulin in their blood, it can lead to hypoglycemia.

But hypoglycemia isn’t limited to people with diabetes. It can happen to anyone if their body can’t properly restore blood sugar to normal levels on its own.

Can Lupus Cause Low Blood Sugar?

“I have always had bouts of low blood sugar, but I am not diabetic,” shared one MyLupusTeam member. Having lupus can contribute to low blood sugar in several ways, related both to the condition itself and to its treatment.

Autoantibodies

The immune system normally makes proteins called antibodies that protect the body from foreign invaders such as bacteria and viruses. However, in people with systemic lupus erythematosus (SLE), the immune system can produce autoantibodies — antibodies that mistakenly target their own healthy tissue.

In rare cases, the immune system makes autoantibodies that target insulin receptors, interfering with the body’s ability to regulate blood glucose levels. This can lead to a rare condition called type B insulin resistance syndrome (TBIRS). This condition can cause hyperglycemia and life-threatening hypoglycemia. Case studies have found that about 1 in 3 people diagnosed with TBIRS also have SLE.

Antimalarial Medications

Hypoglycemia is a rare but possible side effect of antimalarial drugs such as hydroxychloroquine (Plaquenil) that are commonly used to treat lupus. Some MyLupusTeam members have experienced this firsthand. “I have noticed hypoglycemia symptoms since starting Plaquenil,” shared one member.

Learn more about how hydroxychloroquine works.

Adrenal Insufficiency and Corticosteroid Treatment

Adrenal insufficiency happens when the adrenal gland doesn’t make enough of the hormone cortisol. Cortisol is one of the hormones that can help raise blood sugar levels.

People with lupus may develop adrenal insufficiency if they stop taking corticosteroids (steroids) — such as prednisone and methylprednisolone — after taking them for a long time. When corticosteroids are taken for more than a few weeks, your adrenal glands may reduce or stop making cortisol. That’s because corticosteroids mimic the effects of cortisol.

If you suddenly stop taking steroids, the sudden lack of cortisol can cause low blood sugar and other serious symptoms. That’s why corticosteroids should always be stopped slowly by lowering the dosage little by little.

Long-term corticosteroid use can also raise blood glucose levels and increase the risk of developing type II diabetes.

Critical Illness

Severe illnesses such as kidney failure or end-stage liver disease can make it difficult for the body to regulate blood sugar levels. Because SLE can affect any part of the body, including the liver and kidneys (lupus nephritis), complications like lupus nephritis can lead to serious kidney disease or kidney failure — and in some cases, hypoglycemia.

Lupus and Diabetes

If you have lupus, you might also experience the opposite of hypoglycemia — hyperglycemia, or high blood sugar. For most people, a blood glucose level of 125 mg/dL after at least eight hours without food is considered hyperglycemia. Having hyperglycemia on more than one occasion is usually a sign of diabetes.

Some studies have found that people with lupus may be more likely to develop type 2 diabetes. However, researchers are still investigating how lupus and diabetes are linked. A 2024 analysis that reviewed 37 different studies found that, overall, people with SLE didn’t have a higher risk of developing diabetes compared to the general population. In fact, taking antimalarial medications may actually lower the risk of diabetes.

Still, many people with SLE do develop diabetes. “I think lupus is the reason I have diabetes,” shared one MyLupusTeam member.

How Can Lupus Cause High Blood Sugar?

Even though the overall risk of diabetes with SLE is still being researched, many people with lupus experience hyperglycemia. High blood glucose levels can stem from both the disease process itself and from certain lupus treatments.

Inflammation and Insulin Resistance

Lupus causes chronic inflammation throughout the body. This inflammation can trigger the release of inflammatory substances called cytokines, which can make your cells less responsive to insulin. When your cells don’t respond properly to insulin, it’s called insulin resistance.

With insulin resistance, your body has a harder time controlling blood glucose levels, causing glucose to build up in the bloodstream — a condition known as hyperglycemia. Over time, hyperglycemia related to insulin resistance can lead to type 2 diabetes.

Corticosteroids

Hyperglycemia is one of the most common side effects of taking corticosteroids. Although stopping steroids suddenly can cause blood sugar to fall, taking them can have the opposite effect — raising blood sugar levels.

Research shows that more than half of people who receive high doses of steroids in the hospital experience hyperglycemia. Steroids can cause hyperglycemia in several ways, including by:

• Causing or worsening insulin resistance
• Increasing glucose production in the liver
• Changing how the pancreas works
• Increasing appetite and weight gain

Taking steroids for a long period of time is also linked to a higher risk of developing diabetes.

Calcineurin Inhibitors

Calcineurin inhibitors — including cyclosporine (available as Gengraf, Neoral, or Sandimmune) and tacrolimus (Prograf) — are most often used to treat lupus nephritis or to prevent organ transplant rejection. Research has also shown a link between this class of medications and a higher risk of developing diabetes.

Tips for Managing Blood Sugar

If you’re worried about your blood sugar levels, talk with your doctor about the best treatment options for you. They may ask you to keep track of your blood sugar with a glucose monitor. For some people, blood sugar monitoring is part of their regular lupus care.

If you feel the symptoms of low blood sugar, you can treat it by eating or drinking 15 grams of fast-acting carbohydrates. “I usually have a banana and a freshly squeezed glass of orange juice,” shared one MyLupusTeam member. Other quick options include 4 ounces of nondiet soda or glucose tablets or gel (follow the package instructions).

To help prevent high blood sugar, especially if you’re taking corticosteroids, focus on maintaining healthy lifestyle habits. Having lupus and diabetes increases your risk of heart disease. To stay healthy during your lupus treatment, eat a balanced diet with plenty of fruits and vegetables and get as much regular exercise as your condition allows.

Managing lupus and diabetes together can be challenging, but with the right care plan, it’s possible to protect your overall health and reduce your risk of complications such as heart disease.

Join the Conversation

On MyLupusTeam, people share their experiences with lupus, get advice, and find support from others who understand.

Have you noticed changes in your blood sugar levels while managing lupus? Let others know in the comments below.