Diabetic neuropathies are a family of nerve disorders caused by diabetes. It has been defined as presence of symptoms and/or signs of peripheral nerve dysfunction in diabetics after exclusion of other causes, which may range from hereditary, traumatic, compressive, metabolic, toxic, nutritional, infectious, immune mediated, neoplastic, and secondary to other systemic illnesses.
About 60 to 70 percent of people with diabetes have some form of neuropathy. People with diabetes can develop nerve problems at any time, but risk rises with age and longer duration of diabetes. The highest rates of neuropathy are among people who have had diabetes for at least 25 years. Diabetic neuropathies also appear to be more common in people who have problems controlling their blood glucose, also called blood sugar, as well as those with high levels of blood fat and blood pressure and those who are overweight.
Types of Diabetic Neuropathy
There are different types of diabetic neuropathy. The distinction depends upon which types and location of nerves are affected.
- Diabetic peripheral neuropathy refers to damage to peripheral nerves, most commonly the nerves of the feet and legs.
- Diabetic proximal neuropathy affects nerves in the thighs, hips, or buttocks.
- Diabetic autonomic neuropathy affects the autonomic nervous system, the nerves that control body functions. For example, it can affect nerves of the gastrointestinal, urinary, genital, or vascular systems.
- Diabetic focal neuropathy affects a specific nerve or area at any site in the body.
Neuropathy is damage to nerves, and diabetic neuropathy is damage to nerves that occurs as a result of diabetes. Diabetes is thought to damage nerves as a result of prolonged elevated levels of blood glucose. Diabetic neuropathy can affect different parts of the body, and symptoms can range from mild to severe. Diabetic neuropathy is the most common complication of diabetes.
Causes
High glucose and lipid (fat) levels in the blood, and the toxic byproducts they generate through their metabolism, are thought to be the major causes of neuropathy associated with diabetes. However, good glucose control in people with type 1 diabetes can reduce neuropathy by 60 per cent.
It’s possible that elevated blood glucose levels damage the tiny blood vessels that lead to the nerves. If the blood vessels are damaged, they don’t bring oxygen and nutrients to the nerves as they should, which eventually can cause nerve damage.
Other factors may include –
- Age – Diabetic neuropathy takes time to develop, so it’s much more common in older people who have had diabetes for 25 years or more.
- Genetic factors – Unrelated to diabetes that make some people more susceptible to nerve damage.
- Lifestyle choices – It seems that alcohol and smoking make the symptoms of neuropathy worse.
- Nerve injury – Whether the nerves have been damaged through inflammation or through a mechanical injury (such as nerve compression associated with carpal tunnel syndrome), it’s possible the previously-damaged nerves are more susceptible to developing diabetic neuropathy.
Risk Factors
The longer a person has diabetes and the worse the control of their diabetes, the more likely they will develop diabetic neuropathy.
Those people experiencing complications of their diabetes elsewhere in their body (such as in the kidneys, heart or eyes) are also more likely to have or develop neuropathy, as the same factors that cause these problems also contribute to neuropathy. Smoking, high blood pressure and being overweight also make it more likely that people with diabetes will get nerve damage.
Symptoms
The symptoms of diabetic neuropathy depend on what type of neuropathy the person has. Symptoms are dependent on which nerves have been damaged. In general, diabetic neuropathy symptoms develop gradually; they may seem like minor and infrequent pains at first, but as the nerves become more damaged, symptoms may grow.
As mild symptoms can indicate the beginning of neuropathy, the following should be noted – pain, numbness, weakness, or tingling—even if it seems insignificant.
Peripheral Neuropathy Symptoms – Peripheral neuropathy affects nerves leading to the extremities—the feet, legs, hands, and arms. The nerves leading to the feet are the longest in the body, so they are the most often affected nerves (simply because there’s more of them to be affected). Peripheral neuropathy is the most common form of diabetic neuropathy. The symptoms include –
- Pain
- Numbness (loss of feeling)
- Tingling
- Muscle weakness
- Muscle cramping and/or twitching
- Insensitivity to pain and/or temperature
- Extreme sensitivity to even the lightest touch
Symptoms get worse at night.
Proximal Neuropathy Symptoms – Proximal neuropathy affects the buttocks, hips, thighs, and legs. Its symptoms aren’t usually long-term; they may go away after several weeks or months.
Symptoms include –
- Weakness in the legs
- Trouble standing up from a seated position without help.
Autonomic Neuropathy Symptoms – The autonomic nervous system is in charge of the “involuntary” functions of the body. It keeps the heart pumping and keeps the digestion healthy.
- Cardiovascular System
- Dizziness just after standing
- Fainting just after standing
- Irregular heart rate
- Digestive System
- Bloating
- Constipation
- Diarrhea
- Nausea
- Vomiting
- Eyes
- Vision trouble at night or during sudden light changes (e.g., when stepping into a dark building from the sunlight)
- Reproductive System
- Sexual problems—erectile dysfunction in men; vaginal dryness in women
- Sweat Glands
- Profuse sweating, especially at night or when eating particular foods (cheese commonly causes excessive sweating, for example, although that’s not true for every person with diabetic neuropathy)
- Reduced sweating, especially in the legs and feet
- Urinary System
- Bladder dysfunction
Focal Neuropathy Symptoms – This affects the head, torso, or legs. Symptoms include –
- Head
- Vision trouble—double vision, ache behind an eye, difficulty focusing
- Sudden paralysis of one side of the face (Bell’s palsy)
- Torso
- Pain in the chest
- Pain in the stomach
- Pain on the side
- Pain in the low back
- Legs
- Pain in the front of the thigh
- Pain on the outside of the shin
- Pain on the inside of the foot
Treatment
he first treatment step is to bring blood glucose levels within the normal range to help prevent further nerve damage. Blood glucose monitoring, meal planning, physical activity, and diabetes medicines or insulin will help control blood glucose levels. Symptoms may get worse when blood glucose is first brought under control, but over time, maintaining lower blood glucose levels helps lessen symptoms. Good blood glucose control may also help prevent or delay the onset of further problems. As scientists learn more about the underlying causes of neuropathy, new treatments may become available to help slow, prevent, or even reverse nerve damage.x`
Medications – People with severe nerve pain may benefit from a combination of medications or treatments and should consider talking with a health care provider about treatment options.
Medications used to help relieve diabetic nerve pain include – Tricyclic antidepressants, such as amitriptyline, imipramine, and desipramine (Norpramin, Pertofrane) and other types of antidepressants, such as duloxetine (Cymbalta), venlafaxine, bupropion (Wellbutrin), paroxetine (Paxil), and citalopram (Celexa) Anticonvulsants, such as pregabalin (Lyrica), gabapentin (Gabarone, Neurontin), carbamazepine, and lamotrigine (Lamictal), Opioids and opioidlike drugs, such as controlled-release oxycodone, an opioid; and tramadol (Ultram), an opioid that also acts as an antidepressant.
Treatments that are applied to the skin—typically to the feet—include capsaicin cream and lidocaine patches (Lidoderm, Lidopain). Studies suggest that nitrate sprays or patches for the feet may relieve pain. Studies of alpha-lipoic acid, an antioxidant, and evening primrose oil suggest they may help relieve symptoms and improve nerve function in some patients.
A device called a bed cradle can keep sheets and blankets from touching sensitive feet and legs. Acupuncture, biofeedback, or physical therapy may help relieve pain in some people. Treatments that involve electrical nerve stimulation, magnetic therapy, and laser or light therapy may be helpful but need further study. Researchers are also studying several new therapies in clinical trials.
Treating gastroparesis – For gastroparesis, in which the stomach is not emptying properly, physicians at Joslin may prescribe metoclopramide (Reglan®), which will help the stomach push food and get it through the rest of the digestive process. These may be used in conjunction with sucralfate (Carafate®), which “helps to sop up extra acid that may be sitting in the stomach,” Dr. Gibbons says.
Treating bladder neuropathy – For those experiencing bladder neuropathy, which results in the bladder never completely emptying, bethanechol (Urecholine®) may be prescribed. “This is a urine propellant that helps to keep the bladder clear,” says Dr. Gibbons. “Because patients with this problem will be more likely to develop frequent urinary tract infections, the physician may also prescribe chronic antibiotic therapy to try and keep the bacterial count in the bladder and urinary tract at a manageable level.”
Treating impotence – Impotence in men that is a result neuropathy or blood vessel damage (versus psychological causes or due to medications such as anti-depressants or blood pressure medication) can be treated using certain drugs that are either inserted into the end of the penis or injected to cause an erection before intercourse. Vacuum devices that enable an erection to be achieved or a surgically implanted prosthesis are also options to be explored with a physician.
Alternative Treatment
- Alpha lipoic acid is one if the most important nutrients to consider for diabetes. Alpha Lipoic acid has been evaluated for blood sugar control, and it may also be considered in diabetic neuropathy and kidney disease. Alpha-lipoic acid may improve symptomatic diabetic polyneuropathy.
- Acetyl-L-carnitine is helpful in the treatment of diabetic neuropathy. It improves pain, nerve regeneration, and vibratory perception in patients with chronic diabetic neuropathy.
- Benfotiamine has been evaluated in diabetic neuropathy with positive results
- B vitamins could be helpful, perhaps combined with gabapentin (Neurotin). Vitamin B12 is a possible supplement to take for diabetic neuropathy. Vitamin B12 may be more effective than nortriptyline in improving painful diabetic neuropathy. It is more effective than nortriptyline for the treatment of symptomatic painful diabetic neuropathy.
- Ginkgo biloba herbal extract has the best effect with the combination of folate for diabetic neuropathy.
- Capsaicin applied to the skin, capsaicin cream can reduce pain sensations in some people. Side effects may include a burning feeling and skin irritation.
- Vitamin B6 deficiency may be associated with the development of peripheral neuropathy. In addition, in the form of pyridoxine HCl, high doses of B6 have been implicated as a cause of PN.
- Chromium is an essential mineral, chromium plays an important role in facilitating glucose metabolism.
- Coenzyme Q10 is a cofactor used in oxidative respiration and is produced endogenously. Supplementation of coenzyme Q10 is especially popular for cardiovascular diseases.
- Magnesium is an abundant mineral in the human body involved in numerous biochemical processes, including glucose metabolism. It Increases insulin sensitivity.
- Omega-3 polyunsaturated fatty acids (PUFAs) are one of the most common dietary supplements taken in the United States. Studies indicate reductions in coronary artery disease and sudden cardiac death based on omega-3 PUFA intake. In patients with type 2 diabetes, a meta-analysis of omega-3 PUFA supplementation set of type 2 diabetes.60
- Vanadium is a mineral with no known biological importance or deficiency-associated disease.