Diabetes and peripheral neuropathy
Diabetic neuropathy is a type of nerve damage that can occur if you have diabetes. It is a common serious complication of diabetes. High blood sugar can injure nerve fibres throughout your body, but diabetic neuropathy most often damages nerves in your legs and feet.
Depending on the affected nerves, symptoms of diabetic neuropathy can range from pain and numbness in your extremities to problems with your digestive system, urinary tract, blood vessels and heart. For some people, these symptoms are mild; for others, diabetic neuropathy can be painful, disabling and even fatal.
Damage to nerves and blood vessels: Chronically high blood sugar levels damage nerves not only in your extremities but also in other parts of your body. These damaged nerves cannot effectively carry messages between the brain and other parts of the body.
This means you may not feel heat, cold, or pain in your feet, legs, or hands. If you get a cut or sore on your foot, you may not know it, which is why it's so important to inspect your feet daily. If a shoe doesn't fit properly, you could even develop a foot ulcer and not know it. The consequences can be life-threatening. An infection that won't heal because of poor blood flow causes risk for developing ulcers and can lead to amputation, even death. This nerve damage shows itself differently in each person. Some people feel tingling, then later feel pain. Other people lose the feeling in fingers and toes; they have numbness. These changes happen slowly over a period of years, so you might not even notice it. Because the changes are subtle and happen as people get older, people tend to ignore the signs of nerve damage, thinking it's just part of getting older.
Other factors that may contribute to diabetic neuropathy include:
Inflammation in the nerves is caused by an autoimmune response. This occurs when your immune system mistakenly attacks part of your body as if it were a foreign organism.
Genetic factors unrelated to diabetes that make some people more susceptible to nerve damage.
Smoking and alcohol abuse, which damage both nerves and blood vessels and significantly increase the risk of infections.
Symptoms of nerve damage from diabetes
Numbness is the most common, troubling symptom of nerve damage due to diabetes. The loss of sensation is a special concern. People describe the early symptoms of peripheral neuropathy in many ways:
v Pins and needles
v Deep stabs
Others describe sharp pain, cramps, tingling, prickling, and burning sensation. Still others have exaggerated sensitivity to touch. The symptoms are often worse at night.
Anyone who has diabetes can develop neuropathy, but these factors make you more susceptible to nerve damage:
Poor blood sugar control: This is the greatest risk factor for every complication of diabetes, including nerve damage.
Length of time you have diabetes: Your risk of diabetic neuropathy increases the longer you have diabetes, especially if your blood sugar isn't well-controlled.
Kidney disease: Diabetes can cause damage to the kidneys, which may increase the toxins in the blood and contribute to nerve damage.
Overweight: Having a body mass index greater than 24 may increase your risk of developing diabetic neuropathy.
Smoking: Smoking narrows and hardens your arteries, reducing blood flow to your legs and feet. This makes it more difficult for wounds to heal and damages the integrity of the peripheral nerves.
Tests and diagnosis
Diabetic neuropathy is usually diagnosed based on your symptoms, your medical history and a physical exam. During the exam, your doctor is likely to check your muscle strength and tone, tendon reflexes, and sensitivity to touch, temperature and vibration.
Your doctor may also conduct tests that include:
Filament test: Sensitivity to touch may be tested using a soft nylon fiber called a monofilament.
Nerve conduction studies: This test measures how quickly the nerves in your arms and legs conduct electrical signals. It's often used to diagnose carpal tunnel syndrome.
Electromyography (EMG): Often performed along with nerve conduction studies, electromyography measures the electrical discharges produced in your muscles.
Quantitative sensory testing: This noninvasive test is used to assess how your nerves respond to vibration and changes in temperature.
Autonomic testing: If you have symptoms of autonomic neuropathy, your doctor may request special tests to look at your blood pressure in different positions and assess your ability to sweat.
Treatments and drugs
Diabetic neuropathy has no known cure. Treatment for diabetic neuropathy focuses on:
v Slowing progression of the disease
v Relieving pain
v Managing complications and restoring function
Slowing progression of the disease
Consistently keeping blood sugar within a target range can help prevent or delay the progression of diabetic neuropathy and may even improve some of the symptoms you already have. Your doctor will determine the best target range for you based on several factors, such as your age, how long you've had diabetes, and your overall health and the presence of other medical conditions.
To help slow nerve damage:
v Follow your doctor's recommendations for good foot care
v Keep your blood pressure under control
v Follow a healthy-eating plan
v Get plenty of physical activity
v Maintain a healthy weight
v Stop smoking
v Avoid alcohol or, if drinking is allowed, drink only in moderation
Several medications are used to relieve nerve pain, but they don't work for everyone and most have side effects that must be weighed against the benefits they offer. There are also a number of alternative therapies, such as capsaicin cream (made from chili peppers), physical therapy or acupuncture that may help with pain relief.
Pain-relieving treatments may include:
Anti-seizure medications: Although drugs such as gabapentin , pregabalin and carbamazepine are used to prescribe for nerve pain. Side effects may include drowsiness, dizziness and swelling.
Antidepressants: Tricyclic antidepressant medications, such as amitriptyline, desipramine and imipramine, may provide relief for mild to moderate symptoms by interfering with chemical processes in your brain that cause you to feel pain, but they also cause a number of side effects, such as dry mouth, sweating, weight gain, constipation and dizziness.
For some people, antidepressants called serotonin and norepinephrine reuptake inhibitors, such as duloxetine, can relieve pain with fewer side effects.
Lifestyle and home remedies
These measures can help reduce your risk of diabetic neuropathy:
Keep your blood pressure under control: Having both high blood pressure and diabetes greatly increases your risk of complications because both damage your blood vessels and reduce blood flow. Try to keep your blood pressure in the range your doctor recommends, and be sure to have it checked at every office visit.
Make healthy food choices: Eat a balanced diet that includes a variety of healthy foods - especially fruits, vegetables and whole grains - and limit portion sizes to help achieve or maintain a healthy weight.
Be active every day: Daily activity protects your heart and improves blood flow. It also plays a major role in keeping your blood sugar and blood pressure under control. The American Diabetes Association generally recommends about 30 minutes of moderate exercise a day at least five times a week.
You can help prevent or delay diabetic neuropathy and its complications by keeping your blood sugar consistently well-controlled, taking good care of your feet and following a healthy lifestyle.
Blood sugar control
Keeping your blood sugar tightly controlled requires continuous monitoring and, if you take insulin, frequent doses of medication. But keeping your blood sugar consistently within your target range is the best way to help prevent neuropathy and other complications of diabetes. Consistency is important because shifts in blood sugar levels can accelerate nerve damage. The American Diabetes Association recommends that people with diabetes have a blood test called the A1C test at least twice a year to find out your average blood sugar level for the past two to three months. If your blood sugar isn't well-controlled or you change medications, you may need to get tested more often.
Foot problems, including sores that don't heal, ulcers and even amputation, are a common complication of diabetic neuropathy. But you can prevent many of these problems by having a comprehensive foot exam at least once a year, having your doctor check your feet at each office visit and taking good care of your feet at home.
To protect the health of your feet:
Check your feet every day: Look for blisters, cuts, bruises, cracked and peeling skin, redness and swelling. Use a mirror or ask a friend or family member to help examine parts of your feet that are hard to see.
Keep your feet clean and dry: Wash your feet every day with lukewarm water and mild soap. Avoid soaking your feet. Dry your feet and between your toes carefully by blotting or patting with a soft towel.
Moisturize your feet thoroughly to prevent cracking: Avoid getting lotion between your toes, however, as this can encourage fungal growth.
Trim your toenails carefully: Cut your toenails straight across, and file the edges carefully so there are no sharp edges.
Wear clean, dry socks: Look for socks made of cotton or moisture-wicking fibres that don't have tight bands or thick seams.
Wear cushioned shoes that fit well: Always wear shoes or slippers to protect your feet from injury. Make sure that your shoes fit properly and allow your toes to move.
Because people with type 2 diabetes may have multiple health problems, doctors don't always diagnose peripheral neuropathy when symptoms first appear. You need to be aware that your pain may be confused with other problems. Make sure your pain is taken seriously. The American Diabetes Association recommends that all people with diabetes have a comprehensive foot exam - either by a doctor or by a foot specialist (podiatrist) - at least once a year. In addition, your feet should be checked for sores, cracked skin, calluses, blisters, and bone and joint abnormalities at every office visit. Everyone with Type 2 diabetes should be screened for diabetic peripheral neuropathy at the time of their diabetes diagnosis and then routinely thereafter. People with Type 1 diabetes should be screened within five years of their diabetes diagnosis and at least annually thereafter.
The writer is a resident physician, Department of Medicine, MARKS Medical College & Hospital