Arthritis and Diabetes: A Common Association

by Thomas Pressly, MD

(This article appeared in Voice of the Diabetic, Volume 7, Number 4, Fall 1992 Edition, published by the Diabetes Action Network of the National Federation of the Blind.)

From the Editor: Dr. Pressly is a practicing rheumatologist at Willis/Knighton Hospital, and a consultant in rheumatology at Shriners Hospital for Crippled Children, in Shreveport, Louisiana. Diabetes is no stranger in the Pressly household. His wife, Tracy, has been an insulin-dependent diabetic for 28 years.

Arthritis and diabetes are both common conditions that affect many Americans. The musculoskeletal system can be affected in diabetes, leading to conditions such as arthritis. For several reasons, diabetics should be aware of this association. In the presence of musculoskeletal complications, the knowledgeable diabetic can decrease pain, improve function and attempt to decrease the progressive severity of some forms of arthritis. Moreover, the diabetic should know that medications used for the treatment of arthritis can interfere with the treatment of diabetes. Modifications in medications sometimes must be made.

Arthritis is defined as inflammation of the joints. There are over 100 different types of arthritis. Almost forty million Americans have these disorders. Fourteen million Americans have diabetes mellitus. These common disorders can occur together. As stated previously, medications used in the treatment of one disorder can lead to the development of the other and/or can interfere with its treatment.

The most common types of arthritis are osteoarthritis, rheumatoid arthritis, crystalline induced arthropathies (e.g. gout), and systemic lupus erythematosus (SLE). Osteoarthritis is also known as "degenerative joint disease" or the "wear-and-tear form" of arthritis. Occuring commonly in families, it has recently been proven to be an inherited disorder. It commonly affects the hands, spine, hips, and knees. This form of arthritis is usually limited, affecting only the joints, and is more painful later in the day. It is thought to be caused by a defect in cartilage that results in bone destruction.

Rheumatoid arthritis, in comparison, can affect most of the joints of the body and is associated with prominent morning stiffness and swelling. It can involve internal organs such as the heart and lungs. Early diagnosis is important so that medications called remittive agents, which can slow down the progression of the disorder, can be administered prior to bone destruction.

Crystalline induced arthropathies are disorders such as gout and pseudogout. The joint most often involved in gout is the first metatarsal joint located at the base of the big toe. Many times people wake up with excruciating pain in this joint and then note total resolution of pain within three to four days. Bone destruction can occur with gout, but there are medications that can stop the process. 90 percent of people with gout have one episode. The two most common factors that cause gout to flare are use of aspirin and alcohol. Gout also can be flared with the use of Thiazide diuretics (e.g. HCTZ, Dyazide, Maxide), which are commonly prescribed for high blood pressure. Pseudogout is a form of arthritis caused by the desposition of calcium pyrophosphate crystals. An increased incidence occurs in people who have metabolic disorders such as diabetes mellitus. It commonly affects the knees and wrists. Like gout, it usually appears as a flare of severe pain, swelling and redness in a joint. The condition spontaneously improves in a few days.

Systemic lupus erythematosus is a form of arthritis that can have marked internal organ involvement. Although any age group can be affected, it commonly occurs in women in their twenties. Early diagnosis and close follow-up are essential to treat organ involvement. Lupus is a disorder that can vary in severity. There are ten different sub-types of lupus which can vary from a syndrome of rashes and joint pains to life-threatening brain and kidney involvement. Certain medications--mainly heart medications such as Procanimide and Quinidine--can cause SLE. When the medications are stopped, SLE disappears.

Because osteoarthritis, rheumatoid arthritis, gout and lupus are so common, many people with these disorders will also have diabetes mellitus. Diabetes also has specific musculoskeletal manifestations. Three categories of musculoskeletal disorders are caused by diabetes mellitus. Neuropathies (nerve involvement), arthropathies (disorders of the joints and connective tissues), and problems with skin, tendons and muscles make up the three categories.

Neuropathies

Several forms of neuropathies (nerve problems) can occur in diabetes. Distal sensory and sensory motor disorders involve nerves supplying feeling and muscular control over the hands and feet. Patients note a loss of sensation in a stocking/glove distribution. On examination decreased vibration and position sense and decreased tendon reflexes are found. Neuropathies, inflammations of certain nerves of the body, can result in muscle weakness. The most commonly affected nerves are the cranial nerves to the face. This induces eye muscle weakness and weakness of the muscles of the face. Diabetic amyotrophy damages the nerves to the hip and leg muscles, leading to weakness of the extremities. Infrequently, it will involve the arms. This disorder frequently occurs in those with only mild diabetes and can spontaneously resolve. Radiculopathy is distress to major nerves coming out the back. This may be due to death of the nerve (infarction) and will result in electrical shooting sensations down the legs. This is frequently confused with symptoms of a herniated disc. When there is loss of position sense and loss of a sense of balance when walking, it is called diabetic pseudotabies. (This mimics a common finding in long-standing syphilis.) Autonomic neuropathies can result in decreased blood flow to the brain when standing (orthostatic hypotension) and can cause some people to pass out. Impotence, abnormal sweating (dyshidrosis) and diarrhea can also be due to autonomic neuropathies.

Arthropathies

Several forms of arthropathies (disorders of the joints) occur in diabetes. Osteolysis is erosion of the bone commonly affecting the long bones of the feet and hands. This erosion can cause swelling of the fingers and toes and weakening of the bones. Osteoporosis is the loss of bone substance. It occurs much more frequently in women than in men, and there is an increased incidence in diabetics. Lifelong measures such as diet, regular exercise, and the use of estrogens at menopause can make a tremendous difference in prevention of this potentially devastating disorder.

Charcot joints are joints destroyed due to small fractures of the bone as a result of nerve damage to the joints. Diabetes can lead to a reduction of the blood flow in the small vessels to bones. Charcot joints are generally found in the ankles and feet. At advanced stages, the arch of the foot can collapse, which leads to marked difficulty in walking and a "rocker's sole" appearance on the bottom of the foot. With decreased sensation over the bottom of the feet, ulcerations and calluses can form. Therefore, attention to foot care is very important in diabetes.

Due to problems with the blood supply, nerve damage and impairment of the immune system, infections can easily occur in diabetics. Osteomyelitis is infection of the bone and can easily be caused by objects such as pins, which the patient with foot numbness steps on unknowingly. Adhesive capsulitis is the formation of scar tissue around the joint capsule. This will decrease the motion of a joint. The most frequently affected joints are the shoulders. In most cases, adhesive capsulitis can be treated with therapy and injections with good results. In a large study, 11 percent of diabetic patients had this disorder, and another study showed that 25 percent of patients with adhesive capsulitis were diabetics.

Connective tissue disorders can be specifically related to diabetes. Hyperuricemia (elevation of uric acid) and gout were initially thought to have an increased incidence with diabetes, but this has been refuted. In contrast, diffuse idiopathic skeletal hyperostosis has increased incidence with diabetes. This is deposition of bone substance over the spine and almost looks like wet sand flowing down a castle wall. It is usually asymptomatic despite having striking x-ray features. Flexion contractures occur much more commonly in diabetics. This condition may be due to decreased removal of skin collagen in diabetes compared to the increased synthesis of collagen that occurs in scleroderma. (Scleroderma is a systemic connective tissue disorder consisting of tight skin and various degrees of internal organ involvement. A more serious variant of scleroderma is called progress systemic sclerosis. If the kidneys, lungs or heart are involved, progressive systemic sclerosis can be fatal.) Dupuytren's contractures begin as nodules over the palms of the hands and then result in decreased movement in contracture of the fingers. They can also involve the feet. The "waxy-hand syndrome" (cheiloarthropathy) results in decreased motion of the joints, primarily in the fingers and toes. In this condition, feet and hands can develop tight skin that feels firm and waxy. A simple screen test of this disorder, also known as limited joint mobility syndrome, is to have the patient place both hands on the table, palms down with the fingers fanned. The entire surface of the fingers makes contact in normal persons.

Problems With Skin, Muscle, and Tendons

According to one study performed by Rosenbloom, patients who had been diabetic an average of sixteen years with the presence of stiff joints also had an increased incidence of eye and kidney damage.

Tenosynovitis is the formation of nodules over the sheaths that go around the tendons in the fingers and toes. There is an increased incidence of nodule formation of the tendon sheaths in diabetics. This can result in what is known as a "trigger finger" or "catching of the digits" (in toes or fingers) on movement. Beginning in the elbow, the tendon runs to the palm where it branches out into each finger, ending at the tip. Each branch of the tendon is surrounded by a sheath which runs from the base to the tip of each finger. In tenosynovitis, when the finger is bent, nodules (located in the palm of the hand) may catch on the sheath, causing the finger to be locked in place. Hence the term "trigger finger." The finger can be straightened by using the other hand to pull the finger forward; however, this is painful. The condition is treatable with finger exercises, steroid injection, or surgery.

Finally, circulated antibodies or immunoglobins directed toward different structures are increased in type-B insulin-resistant diabetes mellitus. This type of diabetes is due to antibodies directed against the insulin receptors, resulting in increased glucose. There has been an association of this disorder with systemic lupus erythematosus, Sjogren's syndrome (mainly manifested by dry mouth and dry eyes), and progressive systemic sclerosis (marked skin tightness and potentially devastating involvement of internal organs such as kidneys, lungs or heart). Progressive system sclerosis is a more serious, possibly fatal variant of scleroderma, which is mentioned above.

The treatment of arthritis includes rest, which is particularly important in rheumatoid arthritis and systemic lupus erythematosus. The use of hot and cold packs (thermotherapy) can be very helpful in decreasing pain and assisting with motion exercise. Protective splints can be very helpful with active arthritis.

Numerous medications are used to treat arthritis. Analgesics such as Tylenol decrease pain. Nonsteroidal, anti-inflammatory medications such as aspirin, Motrin and Voltaren decrease swelling and pain. Disease-modifying agents, such as gold, can be very helpful in patients with rheumatoid arthritis. Such agents delay or prevent severe bone destruction and decrease pain and swelling. Urate-lowering agents are used to decrease the production of uric acid, which leads to gout. Steroids are used for treatment of lupus, vasculitis (inflammation of the blood vessels) and in certain types of arthritis. Steroids should be carefully used, particularly with diabetes.

Some surgeries can prevent severe complications from occurring (e.g. tendon ruptures), but they are generally considered as a last resort.

It is important for patients with arthritis and diabetes to be aware of the interactions of medications. Low-dose aspirin has a mild glucose-lowering effect; larger doses of aspirin have a glucose-elevating effect. Oral hypoglycemics can raise blood levels of aspirin, potentially leading to overdosage. Aspirin overdose can lead to complications such as ringing in the ears and stomach pain. Nonsteroidals interact with oral hypoglycemics by increasing their glucose-lowering effect. Steroids increase glucose and can disrupt control in people with diabetes. Finally, antigout medications can interact with oral hypoglycemics to lower the serum glucose, leading to hypoglycemic reactions in some people. Arthritis medications can also be a problem with urine testing in diabetics. Aspirin and nonsteroidal anti-inflammatory medications can cause false-positive results for glucose and ketones.

This has been a very brief overview of interaction of diabetes and arthritis. If you do develop arthritis as a result of or simultaneously with diabetes, many things can be done to assist you, such as exercise programs, rest and attention to foot care, including proper shoes, and prompt treatment of infections of bones and related structures. Medications can be helpful in controlling symptoms and decreasing pain. Remember, some medications can interfere with treatment of diabetes. Although not highly recommended, surgery can be helpful in some instances. It is important that you have a detailed discussion with your doctor if you have both of these disorders because of the interactions between treatments. With 40 million Americans with arthritis and 14 million Americans with diabetes, I am sure some people have both disorders.

For more information, contact the American Diabetes Association, the Arthritis Foundation, and your doctor. I will be more than happy to answer any questions if you would care to write me at 2751 Virginia, Ste. 2E, Shreveport, LA 71103.