How high blood sugar can affect your joints, and 6 ways to protect them

by Adrienne Erin

Stiff shoulders, fingers that catch or lock, hands that won’t lie flat on a table. Many people don’t connect these problems with their blood sugar. But diabetes is linked to several joint and connective tissue conditions, and about half of U.S. adults with diabetes also have arthritis. Here’s what the research shows, and what you can do about it.

Key Takeaways

  • About 52% of U.S. adults with diabetes have arthritis, compared with about 27% of all adults, according to CDC data.
  • People with diabetes are about 5 times more likely to develop frozen shoulder, a painful, stiff shoulder condition. It affects roughly 13% of people with diabetes.
  • High blood sugar can stiffen tendons, ligaments and joint tissues through a process called glycation.
  • The link between diabetes and osteoarthritis is less clear than often claimed. Excess body weight, which raises the risk of both, appears to explain much of it.
  • Managing blood sugar, staying active and maintaining a healthy weight can help protect your joints.

How high blood sugar affects joints

When blood sugar stays high, extra glucose attaches to proteins in the body, including collagen, the main building block of tendons, ligaments, cartilage and joint capsules. This forms compounds called advanced glycation end products, or AGEs.

AGEs build up slowly over years. They make collagen stiffer and less elastic, a bit like a rubber band that’s been left in the sun. This can limit how easily joints move and make tissues more prone to injury and slower to heal.

High blood sugar is also linked to low-grade inflammation and damage to small blood vessels and nerves, which can affect how joints and the tissues around them are maintained and repaired.

Joint conditions linked to diabetes

Some conditions are clearly more common in people with diabetes:

  • Frozen shoulder (adhesive capsulitis): The shoulder becomes painful and very stiff, sometimes for a year or more. A 2016 review found people with diabetes were about five times more likely to develop it.
  • Trigger finger: A finger catches, locks or snaps when you bend or straighten it, due to a thickened tendon or tendon sheath.
  • Diabetic stiff hand (cheiroarthropathy): The skin on the hands becomes thick and waxy, and the fingers lose flexibility. A simple check is the “prayer sign”: if you can’t press your palms and fingers flat together, mention it to your doctor.
  • Dupuytren’s contracture: Tissue in the palm thickens and pulls one or more fingers into a bent position.
  • Carpal tunnel syndrome: Pressure on a nerve in the wrist causes numbness, tingling and weakness in the hand.
  • Charcot foot: In people with nerve damage in the feet, bones and joints can weaken and collapse, sometimes after a minor injury that isn’t felt. It’s uncommon but serious.

What about osteoarthritis?

Osteoarthritis, the most common type of arthritis, involves gradual breakdown of joint cartilage. It’s often said that diabetes causes it, but the research is mixed.

A 2020 analysis of 31 studies involving about 295,000 people found that once body weight was taken into account, diabetes wasn’t an independent risk factor for osteoarthritis. A more recent review found a modest link. Researchers say the overlap is largely explained by excess weight, which puts more stress on joints and drives inflammation, and which also raises the risk of type 2 diabetes.

Either way, the conditions often travel together, and they can make each other harder to manage. Joint pain can make it difficult to exercise. In CDC data, about 30% of adults with both diabetes and arthritis were physically inactive, compared with about 11% of adults with neither condition. Less activity can then make blood sugar and weight harder to control.

6 ways to protect your joints

1. Keep your blood sugar in your target range. Work with your doctor on your A1C goal. Better long-term control may slow the buildup of AGEs in tissues.

2. Move every day. Low-impact exercise like walking, swimming, water aerobics and cycling strengthens the muscles that support your joints and helps lower blood sugar. Aim for about 150 minutes a week, broken into short sessions if needed.

3. Stretch regularly. Gentle range-of-motion exercises for your shoulders, hands and fingers can help maintain flexibility. If you notice stiffness, start early, since frozen shoulder and hand stiffness are easier to manage when caught early.

4. Build strength. Strength training two or three times a week supports your joints and helps your muscles use glucose.

5. Maintain a healthy weight. Losing even a modest amount of weight reduces the load on your knees and hips. In one study of adults with knee osteoarthritis, each pound lost removed about four pounds of pressure from the knee with each step.

6. Eat for steady blood sugar. Focus on vegetables, beans, whole grains, nuts, fish and other lean proteins, and limit sugary drinks, refined carbs and ultra-processed foods. These choices also help with weight and inflammation.

When to see a doctor

Talk to your doctor if you have:

  • Shoulder pain and stiffness that limits reaching overhead or behind your back
  • A finger that catches or locks
  • Hands you can’t flatten, or thickened skin on your hands
  • Numbness or tingling in your hands or feet
  • A warm, swollen or red foot, especially if you have nerve damage. This needs prompt attention.

Physical therapy, splints and other treatments can help. If you’re offered a steroid injection for joint pain, ask about checking your blood sugar afterward, since steroids can raise it for several days.

Be wary of supplements marketed as a fix for joint pain or blood sugar. Most aren’t backed by strong evidence, and some can interact with diabetes medications.

This isn’t a substitute for medical advice. Talk to your doctor about joint pain, especially if you have diabetes.

Sources:

Adrienne Erin

Adrienne holds a Bachelor of Science in Kinesiology, where she developed a strong foundation in exercise physiology and human nutrition. Before joining DailyHealthPost, she spent several years writing about health and wellness topics, translating nutrition and fitness research into practical guidance for everyday readers.

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