A patient with diabetes may share that they’ve been experiencing persistent knee pain. Could this be an overlooked symptom of diabetes? Understanding more about knee pain can help you treat your patients with diabetes more effectively and holistically.

Ongoing knee pain can pose several issues for patients, including mobility struggles and quality-of-life concerns. Here are a few ways to provide comprehensive care to your patients. 

The Lesser-Known Effect of Diabetes

Knee pain is a common symptom among individuals with diabetes that may be overlooked or thought to be unrelated to having diabetes, according to Scott Isaacs, MD, president of the American Association of Clinical Endocrinology and adjunct assistant professor at Emory University in Atlanta.

“Many patients, and even clinicians, tend to focus on more classic complications, like painful neuropathy or numbness in the feet, but diabetes can affect the joints, including the knees,” Isaacs said. 

One obvious association is that of obesity and chronic osteoarthritis, especially in weight-bearing joints, like the knee. However, diabetes itself can also have an effect, he said. 

Furthermore, both elevated blood sugar and obesity lead to chronic inflammation. Inflammation can damage the tissues in and around the joints, causing pain, swelling, and stiffness. 

“Neuropathy is nerve damage, caused by damage to the small blood vessels of the nerves, which results in pain, numbness, or tingling,” Isaacs said. “Inflammation from high glucose levels can directly affect the joints and surrounding tissues, leading to a different kind of pain — more like arthritis than neuropathy. However, both arthritis and neuropathy can occur together in people with diabetes, magnifying the pain and discomfort.” 

Primary care doctors should also be aware that high blood sugar levels, over time, can damage blood vessels and connective tissues, leading to inflammation and joint pain.

“I find it helpful to explain to patients that pain in the knees can be from diabetes itself, not just excess weight,” Isaacs said. “Just as diabetes can affect the nerves and blood vessels in the feet, it can also impact the knees, making them more prone to pain, stiffness, and even arthritis.” 

Assessing Knee Pain

The most common causes of chronic knee pain are osteoarthritis (wear and tear of the knee joint), as well as tendinitis and other overuse injuries, according to Scott J. Pilla, MD, assistant professor of medicine at Johns Hopkins University School of Medicine in Baltimore.

Diabetes, obesity, and other metabolic conditions are risk factors for osteoarthritis, and they often coexist in many patients, Pilla said.

“It’s a common thing that patients will bring up in visits and ask for help addressing,” he said. “Doctors don’t usually screen for pain symptoms (as in, they don’t often ask patients whether they have pain unless the patient prompts them), so for patients, it’s important to let the doctor know when there is a new pain symptom.” 

Therapeutic Strategies for Patients

Talk to your patients to understand the scope of the knee pain. “To recognize knee pain early, I recommend routinely screening for musculoskeletal symptoms during diabetes appointments,” said Isaacs. “If a patient reports knee pain, assess the severity, duration, and impact on daily activities.” 

Therapeutic strategies that Issacs suggests include: 

• Optimizing glucose control to reduce inflammation and prevent further joint damage
• Suggesting low-impact physical activity — such as swimming, cycling, or walking — to strengthen muscles around the knee and improve joint function without excessive strain
• Making a referral to physical therapy for personalized exercise programs to enhance flexibility, strength, and mobility
• Encouraging weight loss to decrease pressure on the knees (One pound of weight lost translates to approximately 4-5 pounds of less pressure on the knees, Isaacs said.)
• Introducing pain management medications, such as acetaminophen or NSAIDs, with caution due to potential side effects

When a Referral Is Warranted

Once the cause of knee pain is determined, targeted treatment can begin. For example, if there is neuropathic arthropathy, the patient should be seen by an orthopedist and may need to wear a cast to stabilize the joint, said Pilla. 

But for more common causes of joint pain (osteoarthritis, tendinitis), the most effective long-term therapies are physical therapy, home exercises and stretching, and weight loss, Pilla said. 

Referral to a rheumatologist, or orthopedic specialist, is warranted if the knee pain is severe, persistent, or rapidly worsening or if there is significant swelling, redness, or instability, said Isaacs.

Referrals should also be made if the patient cannot bear weight or has signs of joint infection or if there is suspicion of advanced joint disease, such as Charcot joint and severe osteoarthritis, or concern for other types of arthritis, such as rheumatoid or psoriatic arthritis, he said. 

A Whole-Person Approach to Diabetes Care

Even when referring patients to a specialist, it’s important to keep in mind that diabetes management is more than just controlling blood sugar; it is about supporting the whole person and associated comorbidities, Isaacs said.

“Joint pain, especially in the knees, can impact quality of life and mobility, leading to weight gain and worsening of diabetes as a viscous cycle, so by taking a complications-centric approach that includes early recognition, patient education, lifestyle modification, and multidisciplinary care, we can help our patients address knee pain in diabetes,” Isaacs said.