Diabetes is notorious for causing foot problems. In fact, it is the number one cause of lower limb amputations in the United States. In 2001, the latest year for which statistics are available, some 82,000 amputations—over half of all performed—were caused by diabetes.
But it doesn’t have to be this way. You don’t have to end up losing a limb because you have diabetes. It is estimated at least 50% of the amputations that occur each year in people with diabetes could be prevented through proper care of the feet and legs. By learning about the risks for foot problems and ways to take proper care of your feet, you raise your chances of keeping them for a lifetime.
Are you at risk?
The American Diabetes Association (ADA) has identified an increased risk of ulcers and amputations in the following groups of people with diabetes:
- Those who have had diabetes for ten years or longer
- People whose blood glucose control is less than optimal
- People who already have other diabetes complications, such as cardiovascular (heart) disease, retinopathy (eye disease), or nephropathy (kidney disease)
- People with a history of smoking, because smoking is associated with early development of vascular (blood vessel) complications in diabetes.
In addition, the ADA associates the following foot-related complications with an increased risk of amputation:
- Nerve damage (neuropathy) that has caused diminished sensation in the feet (ability to sense heat, cold, pressure, or pain)
- Alterations in the normal structure and movement of the foot in the presence of neuropathy
- Evidence of increased pressure on a part of the foot, such as redness, bruising, or bleeding under a callus
- Bone deformity in the foot
- Peripheral vascular disease that has caused a decrease or absence of pulses in the feet
- Disease, damage, or deformity of the toenails.
Make sure you have your doctor examine your feet at least once a year to check for the presence of foot problems and to assess your risk of developing problems in the future. (Click here for a checklist of questions to ask your doctor about foot care.) A commonly used test for detecting peripheral neuropathy (damage to the nerves supplying the feet, legs, hands, and arms) involves the physician pressing a Semmes–Weinstein monofilament, a flexible piece of nylon, against several places on the foot. The inability to sense the pressure of the filament at several points indicates neuropathy. To test for peripheral arterial disease, physicians examine the strength of the pulses in the feet and evaluate a person’s ankle–brachial index, which is the ratio of the blood pressure in the calves to the blood pressure in the arms. If you have neuropathy or peripheral arterial disease, your feet should be carefully inspected at every office visit. Your diabetes care team can also advise you on steps you can take to maintain good foot health and keep your risk of foot problems as low as possible.
Risk reduction plan
Here are some of the most important steps you can take now to prevent diabetes-related foot complications:
Blood glucose control. The development of peripheral neuropathy is one of the most important predictors of foot ulcers and amputation. Peripheral neuropathy usually manifests itself as numbness, pricking, or tingling in the fingers or toes, and it can spread up the limb and affect muscles and sweat glands as well. Neuropathy can be prevented or delayed significantly by keeping blood glucose levels as near to the normal range as possible. Optimal blood glucose control can also be beneficial in keeping your blood vessels and circulation healthy and helping the body resist, as well as fight off, infections.
The ADA currently recommends keeping blood glucose levels before meals between 90 mg/dl and 130 mg/dl and keeping blood glucose levels one to two hours after meals below 180 mg/dl for most people. (Both of these ranges assume a meter that gives plasma glucose readings.) Your diabetes care team may recommend slightly different blood glucose goals for you based on personal characteristics such as your age and other health conditions you may have. Be sure you know what your personal blood glucose target range is.
Controlling blood fats. High blood levels of low-density lipoprotein (LDL) cholesterol (the so-called bad cholesterol) and the fats called triglycerides can contribute to atherosclerosis (hardening of the arteries) and heart disease. Atherosclerosis is also a contributor to the development of peripheral arterial disease, which itself increases risk for foot complications by interfering with the healing of wounds. Peripheral arterial disease can be symptomless or it can manifest itself in a number of ways including coolness of the fingers or toes, loss of hair on the hands or feet, or intermittent claudication (pain in the legs or buttocks that starts with activity and subsides with rest).
People with diabetes tend to have LDL levels similar to those of people who don’t have diabetes, but diabetes often causes decreased levels of high-density lipoprotein (HDL) cholesterol (the so-called good cholesterol) and increased levels of triglycerides. The ADA recommends that people with diabetes achieve LDL levels below 100 mg/dl, triglycerides below 150 mg/dl, and HDL levels above 40 mg/dl (some experts recommend that women aim for HDL levels above 50 mg/dl). Depending on your levels and symptoms, your health-care team may recommend dietary changes, including lowering your intake of saturated and trans fats, exercise, and medicines.
Controlling blood pressure. High blood pressure is a major contributor to heart disease, the leading cause of death for people with diabetes. It also increases risks for peripheral arterial disease and impaired circulation to the feet. The ADA advises people with diabetes to attain blood pressures below 130/80 mm Hg. Dietary changes such as decreasing the sodium in your diet, exercising, and medicines are all possible treatments for high blood pressure.
Smoking cessation. As mentioned earlier, smoking is related to early development of vascular complications in people with diabetes. If you smoke, therefore, your risk for foot problems increases; lowering your risk, obviously, involves quitting. Several options are available to assist with smoking cessation such as individual or group counseling and use of nicotine products or certain prescription medicines. Your diabetes care team may be able to offer guidance on choosing an option for you.
Daily foot inspection. Take time to inspect your feet every day. Look at the tops and bottoms of your feet as well as between your toes. Rubbing the back of your hand (which is especially sensitive to temperature) along your foot can help you to detect cool spots, which may indicate impaired circulation, or unusually warm areas, which could be signs of inflammation and infection. If you examine your feet every day, you are likely to notice if something has changed. Check with your diabetes care team if you find a change that concerns you or if you notice any of the following in your feet and legs: redness, swelling, or increased warmth; any change in size, odor, or shape; pain, either at rest or when walking; any open sores; sores that do not heal; ingrown toenails; and corns or calluses (especially if there’s any skin discoloration). In addition, call your diabetes care team if you experience high blood glucose levels for which you can determine no cause; this may be a sign of infection.
Foot care habits. In addition to inspecting your feet every day, practice these healthy foot care habits. Like your blood glucose control regimen, foot care is a daily process. Don’t forget to keep up your foot care even when your routine changes, such as when you’re on vacation, a time when you may be tempted to walk barefoot in the sand or by the pool.
Evaluating footwear. Shoes or slippers should always be worn to protect your feet; however, many foot ulcers start with rubbing from ill-fitting shoes, so it’s important that your shoes fit well and don’t cause any abnormal pressure on your feet. It may be helpful to have your feet measured every time you buy shoes because feet change in size and shape over time. It’s also better to be fitted for shoes in the afternoon or evening rather than first thing in the morning; walking around all day causes your feet to spread, so getting fitted when your feet are at their largest can help you to ensure a comfortable fit.
Properly fitted shoes should fit both the width and length of your feet, allow room for the free movement of your toes, and be well-cushioned. High-heeled footwear or shoes with pointed toes can constrict or place undue pressure on parts of the foot, so they should be avoided. Sandals with straps between the toes can cause irritation or injury. Walking or athletic shoes, which offer padding and support, can be good choices, but people with diabetes who have complications that affect their feet may need special assistance selecting shoes or may need custom-made shoes.
If you have any lack of sensation in your feet (because of neuropathy, for example), it may be difficult to judge how well your shoes fit or sense whether any areas of your feet are being rubbed or irritated by shoe (or even sock) seams. You may want to seek the help of a certified pedorthist in selecting shoes. (See “For More Information” for help in locating a certified pedorthist.)
Some people with lack of sensation in the feet, other changes in the feet caused by diabetes, or a history of foot ulcers may be candidates for orthotics, or specially designed insoles that are worn inside the shoes. Such insoles can be customized and modified to help control the way your foot moves or support the foot to avoid pain and pressure in a certain area. Some special shoes have extra depth to accommodate the placement of inserts. If orthotics don’t do the trick, it may be necessary to get custom-made shoes. Many health insurance plans, including Medicare Part B, offer some coverage for orthotics or custom-made shoes. To qualify for depth-inlay shoes, custom-molded shoes, or shoe inserts under Medicare Part B, your physician must certify that you have diabetes and are being treated, that you need the insert or shoe because you have diabetes, and that you have a condition such as an amputation, foot ulcers, calluses, poor circulation, or foot deformity.
Socks should always be worn with shoes to prevent blisters. People with diabetes should wear socks that fit well (tight socks impair circulation) and are seamless (to prevent blisters). Socks should be made of breathable material such as cotton or wool, ideally blended with a material that draws moisture away from the skin, such as acrylic. (The nylon in stockings or pantyhose is not a breathable fabric, so these should be worn as little as possible.)
Diabetes and foot problems
Even common foot problems such as small cuts, calluses, or ingrown toenails can open the door to serious problems in a person with diabetes, particularly if his blood glucose is not in control. Because such problems can lead to infections and even foot ulcers, don’t ignore even seemingly minor wounds, and don’t hesitate to seek the advice of your health-care provider if a wound doesn’t heal promptly.
Dryness. If not resolved, dry skin can crack, allowing germs to get under the skin, which can lead to infection.
Fungal infections. Athlete’s foot and other fungal infections are more common in people with diabetes. Athlete’s foot can cause cracking of the skin that can allow germs to enter the body.
Calluses. Calluses usually occur as the result of pressure or rubbing in an area of the foot. If not treated, they can sometimes lead to ulceration of the skin tissue underneath. Never try to trim a corn or callus with a razor or knife. Over-the-counter chemical callus removers should also be avoided. See your doctor or podiatrist if you have trouble with thick calluses.
Bone deformity. Diabetes increases the risk of problems such as hammertoe (sometimes called mallet toe or claw toe), which is a change in the position of the toe, causing it to appear curved. Hammertoes increase the likelihood for callus or corn formation due to pressure on the deformed toe. A bunion is a deformity that occurs in the joint of the big toe. The toe is turned inward, causing the joint to protrude outward. A bunion can contribute to pain in the foot, as well as poor fit of shoes, again contributing to abnormal pressures. Charcot foot is a severe deformity in which the arch and normal foot structure break down. Usually, Charcot foot is caused by severe neuropathy. Prompt evaluation and treatment are necessary.
Seeing a specialist
If your feet need special attention, your physician may refer you to one of the following types of specialist:
Neurologist. Neurologists are doctors (M.D. or D.O.) that treat diseases of the nervous system. Tight control of your blood glucose is the best way to prevent or slow the progression of neuropathy, but a neurologist can also help if neuropathy is causing you pain or if you’re experiencing muscle weakness. Neurologists are also able to detect early signs of neuropathy.
Orthopedist. Orthopedists (also M.D. or D.O.) are concerned with the diagnosis, care, and treatment of musculoskeletal disorders. The orthopedist’s scope of practice includes disorders of the body’s bones, joints, ligaments, muscles, and tendons. Orthopedists treat problems such as bunions and hammertoes.
Pedorthist. A certified pedorthist (C.Ped.) has training and certification to design, manufacture, modify, and fit footwear to alleviate lower limb problems. A pedorthist is not a doctor, but some podiatrists are also certified as pedorthists.
Physical therapist. Physical therapists (P.T.) are health professionals who treat movement disorders. They often help people recover from a stroke or injury and also teach people how to avoid injuries. Physical therapists can help people with leg casts (to help ulcers heal), an amputation, neuropathy, or foot deformities to improve their mobility.
Podiatrist. Doctors of podiatric medicine (D.P.M.) are physicians and surgeons who practice on the lower extremities, primarily the feet and ankles. They treat problems from calluses and nail fungus to tumors, fractures, and deformities. They can fit orthotic inserts and design custom-made shoes.
Vascular surgeon. Vascular surgeons (M.D. or D.O.) specialize in treating diseases of the blood vessels. If you develop peripheral arterial disease that affects your feet, a vascular surgeon can perform an angioplasty, place a stent (a device that is placed in a blood vessel to keep it open after an angioplasty has widened it), or perform a bypass operation to improve blood flow to your feet.
The nature of your foot problems will determine which specialist’s expertise may be necessary. In addition to these, there may be a time when another specialist’s assistance is needed.
An ounce of prevention
When it comes to diabetes and foot-care management, an ounce of prevention is worth a pound of cure. Daily attention to your feet, visiting your diabetes care team as recommended, efforts toward reducing your risks for foot problems, and proper treatment when necessary, are all important parts in getting your feet to last your entire lifetime.