Diabetes and arthritis: is there a connection?
Published on 01 October 2009
Arthritis Today’s resident expert Dr Philip Helliwell explains the links between these two common conditions.
Diabetes mellitus (also known as ‘sugar’ diabetes) interferes with the body’s ability to use sugar. It is a long-term condition requiring treatment by diet, pills and often injections of insulin. Generally doctors recognise two types of diabetes. Type I typically occurs in younger people and often requires treatment with insulin. Type 2 occurs in older overweight people and is treated with tablets but there can be a lot of overlap between the two types. There is often a family history of diabetes in both. Early symptoms of diabetes include thirst and passing a lot of urine, and some people lose a lot of weight. The problems with handling sugar, and specifically high blood sugar levels, can eventually lead to complications in the blood vessels, kidneys, eyes, and the nerves to the hands and feet. These complications can be delayed and minimised by controlling the blood sugar with treatment.
People with diabetes are also prone to a number of musculoskeletal complications but the relationship between these complications and the diabetic control is not clear. Many of these problems are not unique to diabetes but occur more frequently in this condition. This short article describes the complications and offers advice on treatment and prevention.
Shoulder pain is probably the most common musculoskeletal disorder which I see associated with diabetes. Specifically the shoulder becomes stiff and painful due to inflammation and thickening of the tissue surrounding the shoulder joint – sometimes known as frozen shoulder. The pain may start following a minor injury or just come out of the blue. Typically the pain builds up to a constant nagging pain which limits the movement of the joint and causes sleep disturbance. The pain is worse in the first 3 months and then subsides gradually, although the stiffness may remain for several months. Sometimes the condition occurs in both shoulders, either one after the other or at the same time.
Treatment consists of taking painkillers and physiotherapy. Sometimes a steroid injection will be given into the shoulder. Physiotherapists will advise on exercises and may offer pain control through such devices as a TENS machine (a device which generates a small electrical current, felt as a tingling sensation, through pads on the skin).
A number of hand problems may occur in diabetes.
Carpal tunnel syndrome
One of the nerves to the fingers (the median nerve) may become trapped as it passes through the tunnel made by the bones and ligaments of the wrist (the carpal tunnel). The first symptom is usually pins and needles felt in the thumb, index and middle fingers of the affected hand. The symptoms are often worse at night causing disturbance of sleep. As the condition progresses the grip may become weaker and the affected fingers become numb.
Initial treatments include using a wrist brace and, sometimes, injection of steroid into the carpal tunnel. If these treatments fail to work, and it is better not to wait too long, then a small operation to ‘release’ the trapped nerve can be performed. Sometimes pins and needles can occur in the hands and feet as a result of diabetic damage to the nerve endings and this can occasionally be confused with carpal tunnel syndrome. It is possible to distinguish between these conditions by performing an electrical test on the hands.
Dupuytren was a French physician who described thickening (known as fibrosis) of the tissues of the palm. It often starts at the outer edge of the palm and appears as a ‘knot’ in the skin. The thickening can progress and involve the tendons (or guiders) to the fingers so that they become bent over towards the palm. This process starts in the fourth and fifth fingers and progresses slowly over many years, although sometimes it may not progress at all. If progression does occur then surgical removal of the thickened tissues may be necessary but it is best not to leave this condition too late.
Diabetic cheiroarthropathy (sometimes known as limited joint mobility)
This complication is unique to diabetes and results from the effect of high blood sugar on the tissues of the hand and foot. The tissues underneath the skin and surrounding the tendons become generally thicker and less supple making it difficult to fully stretch out the fingers and the skin of the fingers and hand may look waxy and thickened. Doctors look for the ‘prayer sign’, asking the patient to put the hands together as if in prayer – a positive prayer sign is seen as an inability to put the hands together fully. From a practical point of view this complication may cause difficulty with hand dexterity and it may cause discomfort as the thickening progresses. Painkillers are sometimes necessary and physiotherapy may help delay progression by keeping the fingers straighter and more mobile.
Diabetic ‘Charcot’ arthropathy (sometimes known as diabetic osteoarthropathy)
This can be a devastating complication of diabetes. Awareness is very important as early treatment can prevent the worst outcome. Charcot was a French physician who described a severe form of arthritis in people who had lost the feeling in a limb. For this condition to occur diabetic damage to the nerves, causing loss of feeling, must already be present. The foot and ankle are most often affected. The condition is sometimes triggered by an injury (such as an ankle sprain). The ankle sprain itself may be relatively minor but the long-term consequences, in terms of inflammation and damage, may be profound.
The usual sequence of events is therefore as follows. The person usually has had diabetes for some time. Damage to the nerve endings in the hands and feet is present and causes symptoms such as burning and pins and needles. A minor injury such as turning the ankle on a pebble or kerb stone may occur but this condition can occur without reason. The pain and bruising from the injury is usually only brief and the ankle or foot may appear to settle down. Unfortunately, after a short period of time the affected area starts to swell, and become warm, painful and stiff. This may progress rapidly until the person starts to limp. If an x-ray is taken at this point it will be clear that the bones and joints are severely affected. If the person continues to walk on this foot then more damage may result.
It is thought that if the condition can be caught early enough then much of the inflammation and damage can be prevented. The foot and ankle must be rested completely. This is usually done by putting a cast or a boot on to the affected leg. People can still get around but the device stops them putting too much weight through the affected limb. It may be necessary to wear this for several weeks. At the same time there are drugs that can be given to suppress the inflammation and to restore the bone loss. Although non-steroidal anti-inflammatory drugs (NSAIDs) are given it is usually necessary to give much stronger anti-inflammatory drugs. Drugs which are effective in bone disorders (such as osteoporosis and Paget’s disease) are also effective in preventing bone loss in this condition. These drugs, called bisphosphonates, are usually given by injection, as a day case in hospital. Several injections may be necessary. Diabetic Charcot arthropathy is serious and can be minimised by early and appropriate treatment. Both patients and their health care providers should be aware and alert to this condition.
General advice for people with diabetes
What are my chances of developing a musculoskeletal complication?
This is impossible to answer. There is some evidence that better diabetic control will help prevent the complications such as kidney disease but not necessarily musculoskeletal complications. And the longer you have diabetes the more likely you will develop a musculoskeletal complication. And don’t forget that if you have evidence of damage to the nerves (peripheral neuropathy) then you will be liable to develop diabetic Charcot arthropathy and you should report any symptoms occurring in your foot and ankle, particularly after an injury, however minor.
Am I at risk of more side-effects from drugs used to treat musculoskeletal complications?
People with diabetes are at increased risk of developing heart disease. This is why it is so important to pay attention to the usual risk factors for heart disease such as smoking, obesity, blood pressure and cholesterol levels. Anti-inflammatory drugs used in musculoskeletal disease are associated with a small but definite increased risk of a heart attack so this should be taken into account when choosing a drug. Current advice is to use the smallest effective dose for the shortest possible time. It is important to remember, however, that these drugs are very helpful and any decision to start them should be taken after a full discussion of the risks and benefits.
What about complementary and alternative therapy?
There is no evidence that alternative treatments are of any use in preventing the complications of diabetes. It is worth noting, however, that many people use glucosamine to help or prevent arthritic symptoms. Glucosamine, as the name suggests, has a sugar molecule within its chemical structure and there were fears that taking this supplement might induce or worsen diabetes. Current evidence and experience indicates that this is not the case and you should therefore have no problems taking this supplement, should you wish. The only warnings with glucosamine are, firstly that is inadvisable for people with shellfish allergy to take it, and, secondly, glucosamine may make Dupuytren’s contracture worse.