What is diabetic neuropathy?
- Diabetic neuropathy is nerve damage that happens in people with diabetes.
- It is more common in men than in women.
- People with diabetic neuropathy can have numbness (loss of feeling), tingling, burning, or pain in different parts of their body.
- The sensation has been described as walking in sand, walking on egg shells, cold, warm, like swollen feet, like pins sticking, like wearing thick socks or boots.
- Most often, the nerves and skin of the feet are affected.
- Diabetic neuropathy also can affect other nerves and areas of skin, blood vessels, and the heart, bowel, bladder, or genitals.
What causes diabetic neuropathy?
- If your blood sugar levels are high, you are more likely to get diabetic neuropathy.
- Over time, high blood sugar levels damage blood vessels and nerves.
- Neuropathy can develop in the pre-diabetic condition.
What can I do to keep from getting diabetic neuropathy?
Treatment of diabetes can delay or prevent diabetic neuropathy. Here are some things you can do:
• Learn as much as you can about diabetes and how to control the disease. Work with your doctor to set goals, such as better blood sugar control and getting more exercise.
• Keep your blood sugar levels within your goal.
- Learn how a healthy diet and exercise can lower your blood sugar levels.
• If you have high blood pressure or a high cholesterol level, take your medicine. Tell your doctor if you cannot take your medicines in the way they are prescribed.
• If you are overweight, ask your doctor what you can do to lose weight.
• Do not use alcohol or tobacco.
• Keep a list of all medicines, supplements (such as vitamins), and herbal products that you take. Write down how much and how often you take them.
• If you take insulin, keep a record of what type, how much, and when you take it.
• Write down your home blood sugar measurements. Also, write down things that upset your blood sugar level, such as certain foods or illness.
- Bring your medicine list, blood sugar record, and insulin record with you when you see your doctor.
Treatment of diabetic neuropathy
Burning Feet: The neuropathies are the most common of the complications of diabetes. They give rise to much suffering among diabetic patients.
Diabetic neuropathy is a debilitating disorder that occurs in nearly 50% of patients with diabetes. It is a finding in both type 1 and type 2 diabetes.
There are three main elements in the treatment regimen:
1. Glycemic control
2. Foot care
3. Treatment of pain
Control of Blood Sugar
The most important treatment for the prevention of diabetic neuropathy is optimal glucose control.
The occurrence of diabetic neuropathy was reduced by 60% over a 10-year period with rigorous blood glucose control in patients with type 1 diabetes.
Similar findings were noted in the Stockholm Diabetes Intervention Study. The effect of hyperglycemia on disease progression appears to be dose-dependent.
In the Oslo Diabetes study each 1 percent rise in hemoglobin A1c (HbA1c) values was associated with a 1.3 m/sec slowing of nerve conduction at eight years.
Established neuropathy
The role of glycemic control in established diabetic neuropathy is uncertain, but several small studies suggest that neuropathic symptoms may improve with intensive antidiabetic therapy.
A practice statement issued by the American Diabetes Association in 2005 recommended that the first step in the management of patients with symptomatic diabetic polyneuropathy should be to aim for stable and optimal glycemic control.
Foot Care
Good glucose control should be combined with foot care. On a daily basis, patients need to inspect their feet for the presence of dry or cracking skin, fissures, plantar callus formation, and signs of early infection between the toes and around the toe nails.
Regular foot examinations by the physician to detect early neuropathy are also an essential component of the treatment of diabetic patients. Once a patient has diabetic neuropathy, foot care is even more important to prevent ulceration, infection, and amputation.
Painful Diabetic Neuropathy
Some patients with diabetic polyneuropathy have painful symptoms. Patients with painful diabetic neuropathy should be treated with a systematic, stepwise approach. Before initiating therapy, it is important to confirm that the pain is due to neuropathy.
The onset of severe pain in the feet and lower limbs can be very distressing and disabling. A herniated disc in the spine will be considered if the pain has developed in relation to recent trauma or its onset is abrupt. In addition, pain due to disc disease is more often unilateral than pain related to peripheral neuropathy.
In the absence of these features, the diagnoses to consider are neuropathy or/and peripheral vascular disease. The physical examination by an experienced neurologist may be helpful (decreased sensation, loss of deep tendon reflexes), but these signs of neuropathy do not necessarily mean that the pain is due to the neuropathy.
Clues that the patient has neuropathic pain:
- the location of pain (feet more than calves)
- the quality of the pain
- the timing of pain (present at rest, improves with walking)
Each of these features is different from those of the pain due to ischemic vascular disease.
It is also important to confirm that the pain is due to diabetic polyneuropathy, and nondiabetic etiologies should be excluded.
Good News!: Spontaneous resolution — The condition is sometimes self-limited, typically by 1 to 1.5 yrs.
Remission is more likely if the onset of symptoms had followed a sudden metabolic change (either an episode of diabetic ketoacidosis or occasionally an improvement in glycemic control), when the duration of diabetes was relatively short, or when marked weight loss preceded the onset of pain.
Pain Control
There are medical options for treating foot pain, due to diabetic neuropthy. These include: Duloxetine and pregabalin as the only drugs formally approved by the European Medicines Agency and by the US Food and Drug Administration (FDA) for the treatment of painful diabetic polyneuropathy.
Both drugs were effective and data suggest similar therapeutic efficacy.
Smaller clinical trials confirm the efficacy of several other drugs or classes of drugs, including tricyclic agents, gabapentin, capsaicin, mexiletine, opioids, and antioxidants. While none of these compounds are approved by the US FDA for the treatment of painful diabetic neuropathy, they are commonly used in clinical practice for that purpose.
How do we Manage Your Diabetic Neuropathy?
Dr. Rosenkilde typically begins treatment of painful diabetic polyneuropathy (DPN) with a tricyclic agent, duloxetine, gabapentin, or pregabalin. The choice of primary medication is tailored specifically to the individual patients needs, potential interactions with other medications and tolerability of side effects. More recently, the American Academy of Neurology has published evidence-based guidlines for treatment of painful diabetic neuropathy, http://www.aan.com/press/index.cfm?fuseaction=release.view&release=935
Tricyclic drugs
Many tricyclic antidepressant drugs (but not selective serotonin reuptake inhibitors) have been found in double-blind, randomized controlled trials to improve symptoms in patients with painful diabetic neuropathy, and a systematic review found that tricyclic antidepressants were more effective for short-term pain relief than traditional or newer generation anticonvulsants
Amitriptyline and nortriptyline are contraindicated in some patients with cardiac disease. Common side-effects of tricyclic antidepressants include dry mouth and somnolence.
We recommend initiating tricyclic therapy with a dose at bedtime. Urinary retention can occur, especially in men with enlarged prostates.
Duloxetine
Duloxetine (Cymbalta), a dual serotonin and norepinephrine reuptake inhibitor, is effective for the treatment of painful diabetic polyneuropathy. Duloxetine showed rapid onset of action and sustained benefit, and it was also effective in relieving pain at night.
Side effects reported by some patients have been nausea, somnolence, dizziness, decreased appetite, and constipation.
Hot flashes and erectile dysfunction were also reported infrequently.
Duloxetine should not be taken with other serotonin or norepinephrine uptake inhibitors but can be combined with anticonvulsant therapy.
Anticonvulsants (anti- seizure medications)
Both newer (gabapentinn (Neurontin) and pregabalin (Lyrica)) and older (sodium valproate (Depakote) and perhaps carbamazepine (Tegretol)) anticonvulsants are useful for treating painful DPN.
Adverse events in some patients were dizziness, somnolence, and peripheral edema. Weight gain occasionally has followed use of valproate, gabapentin and pregabalin. If the dose is not titrated slowly blurry vision, sedation, fatigue and confusion have been reported. In the opinion of Dr. Rosenkilde, pregabalin has more often caused sedation and confusion. It may be habit forming and is classified as a Schedule V drug in the United States.
Venlafaxine
In a randomized controlled trial, extended-release (ER) venlafaxine (Effexor) was evaluated in 244 patients with painful diabetic neuropathy. Nausea and somnolence were the most common side effects of venlafaxine, and blood pressure and cardiac rhythm changes occurred more often with venlafaxine treatment than with placebo.
Opioids
Tramadol (Ultram) have been used on occasion with some success. Morphine sulphate and oxycodone at a daily dose of 10 to 120 mg appears be effective and safe for the treatment of painful diabetic polyneuropathy, as shown in two randomized clinical trials. In the larger of these trials involving 159 patients, oxycodone CR at an average dose of 37 mg daily provided more pain relief than placebo.
Methadone has also been used with success by pain specialists to treat refractory painful neuropathy although no clinical trial data exist to support its effectiveness.
The most frequent adverse effects were nausea, constipation, headache, and somnolence. All opioids have high potential of drug dependence and abuse. The patient may resist stopping these medications when no longer needed for medical reasons.
Topical cream
Capsaicin 0.075% applied four times daily has been associated with modest, but significant improvement in symptoms. Some patients have used lidocaine (Lidoderm 5% patch).
Transcutaneous electrical nerve stimulation (TENS)
Although data are limited, a 2010 guideline from the American Academy of Neurology concluded that TENS is probably effective for reducing pain from diabetic polyneuropathy, based upon small trials.
Combination therapy
Results from small trials suggest that the treatment of neuropathic pain with combinations of drugs from different medication classes is modestly more effective than monotherapy.
NSAID
Non-steroidal anti-inflammatory drugs are effective in patients with musculoskeletal or joint abnormalities secondary to long-standing neuropathy; any joint deformities could be the primary source of pain. Concerns have been expressed that NSAIDs may impair blood circulation of the peripheral nerves and worsen nerve injury due to inhibition of prostacyclin synthesis. The side effects of NSAID are well know and extensively publicized, many can be purchased over the counter without doctor's prescription.
Treatments with doubtful or no benefit
Lamotrigine, oxcarbazepine, lacosamide, mexiletine, clonidine are probably not effective. Low-intensity laser therapy, magnetic field treatment and Reiki therapy are "not recommended".
Alpha-lipoic acid — One of the mechanisms implicated in the pathogenesis of diabetic neuropathy is increased oxidative stress. As a result, antioxidants have been studied for their potential to diminish oxidative stress, improve the underlying pathophysiology of neuropathy, and reduce pain. Some benefits have been reported.
Summary of Recommendations
The treatments for symptomatic diabetic polyneuropathy reviewed here are based on the recommendations of American Diabetes Association and the American Academy of Neurology.
- Exclude nondiabetic etiologies
- Stabilize glycemic control (insulin not always required in type 2 diabetes)
- Antidepressant or anticonvulsant drug(s), topical medication.
- Consider pain clinic referral.
- Nonpharmacologic treatments, such as topical stimulation or physical therapies might be useful.
- Tight glycemic control can prevent, delay, or slow the progression of diabetic neuropathy in patients with type 1 diabetes.
- Patients with diabetes should be educated about proper foot care and should check their feet daily.
- All patients with diabetes should have an annual foot examination by a health care professional.
Tips for Keeping Your Feet Healthy
- Check your feet and shoes.
- Have your doctor check your feet at least once a year or whenever you think anything seems wrong.
- Check your feet every day when you take off your shoes. You may need to use a mirror to check the bottoms of your heels and feet. Also, check your socks for blood or wetness from a foot sore.
- Check inside your shoes every day for torn linings, gravel, and other things that could hurt your feet.
- Call your doctor if you have redness, swelling, infection, pain, numbness, or tingling in any part of your foot.
- Take good care of your feet.
- Wash your feet in lukewarm water every day. Dry your feet well, especially between your toes. Use a soft towel and blot gently (do not rub).
- Keep the skin of your feet smooth by applying a cream or lanolin lotion.
- If your feet sweat easily, dust them with nonmedicated powder (such as baby powder) before you put on your shoes and socks or nylons.
- Keep your toenails trimmed correctly. If necessary, see a podiatrist (a doctor with special training in foot care).
- Wear cotton socks.
- Change your socks every day.
- Choose your shoes carefully.
- The best shoes have a wide toe and good arch support.
- If possible, buy your shoes from a store that has a salesperson who knows how to evaluate how shoes fit.
- Try on shoes at the end of the day when your feet are normally a little swollen. Your podiatrist or family doctor may want to check your new shoes.
- Break in new shoes slowly. Wear the shoes for 1 to 2 hours. Then check your feet for red spots. If you have red spots, do not wear the shoes again until the red spots are gone. Slowly break in new shoes by wearing them one hour longer each day every 3 days.
- If you get calluses or sores from regular shoes, you may need foot orthotics (custom arch supports) or custom-molded shoes.
- Avoid things that are bad for your feet.
- Do not walk barefoot.
- Do not wear stretch socks, nylon socks, socks with inside seams, or socks with an elastic band or garter at the top.
- Do not put hot water, electric blankets, or heating pads on your feet.
- Do not use hydrogen peroxide, iodine, or astringents (such as rubbing alcohol or witch hazel) on your feet.
American Chronic Pain Association (ACPA)Provides self-help coping skills and peer support to people with chronic pain. Sponsors local support groups throughout the U.S. and provides assistance in starting and maintaining support groups.
American Diabetes AssociationNon-profit health organization providing diabetes research, advocacy services, and information, including information on the complications of diabetes, such as diabetic neuropathy.
American Academy of Neurology
