Diabetic neuropathy refers to nerve damage that results from high blood glucose levels. This progressive condition affects a range of nerves in the bodies of some people with diabetes and gets worse with time. Optimizing diabetes treatment helps prevent and manage diabetic neuropathy.
Diabetic neuropathy is the most common complication of diabetes, according to a 2017 report by the American Diabetes Association (ADA).
The ADA reports that diabetic neuropathy causes no noticeable symptoms in up to 50% of cases. However, when symptoms do develop, they often include tingling, numbness, weakness, or pain.
Keeping blood glucose levels within target range may help prevent diabetic neuropathy. It may also stop diabetic neuropathy from getting worse.
Scientists have linked increased blood triglyceride levels to neuropathy progression in people with type 2 diabetes.
They have also found an independent association between obesity and abnormal levels of cholesterol and other fats in the blood and an increased risk of developing neuropathy.
An endocrinologist, a neurologist, and a family physician share their insights on what causes diabetic neuropathy and how to manage or prevent it.
Diabetic neuropathy refers to nerve damage that may develop as a complication of diabetes.
Nerves send signals between the brain and the body, which helps:
- feel sensations
- move the body
- control unconscious bodily processes, such as heartbeat or digestion
There are four main types of diabetic neuropathy:
- Peripheral neuropathy: This condition typically affects the nerves in the feet, legs, and sometimes hands and arms. It can cause tingling, numbness, weakness, and pain.
- Autonomic neuropathy: This type of neuropathy affects the nerves that control internal organs and involuntary processes. It can disrupt heart rate, blood pressure, digestion, and other bodily functions.
- Proximal neuropathy: This disease occurs in the nerves in the thigh, hip, or buttocks. It can cause disabling pain, weakness, and muscle loss.
- Focus neuropathies: This affects single nerves, usually in the hand, foot, leg, torso, or head. It can bring about tingling, numbness, weakness, and pain. It may cause vision changes or facial paralysis if it affects the head.
“Numbness and tingling in the extremities is very common. Many people can still feel things, but they cannot feel pain and temperature as well,” said Dr. Michael L. Rosenberg, a professor of neurology at Hackensack Meridian School of Medicine and JFK Medical Center in Edison, NJ.
“I also ask, do they have autonomic problems? Bladder problems, constipation, diarrhea, nausea, dizziness when they stand up — those might be some presenting symptoms,” Dr. Rosenberg added.
Diabetic neuropathy is nerve damage occurring due to chronically high levels of glucose, or sugar, in the blood. Symptoms usually develop about 10–20 years after a person has received a diagnosis of diabetes.
In people with diabetes, the body cannot properly make or use insulin, a hormone that allows glucose into the body’s cells. Untreated diabetes eventually leads to high levels of glucose in the blood.
“This causes what [is] known as oxidative stresses on the system,” said Dr. Barbara Keber, the chair of family medicine at Glen Cove Hospital on Long Island, NY. “It interrupts the normal energy process in the nerve cells, causing them to become damaged.”
Over time, high blood glucose levels damage the nerves that send signals between the body and the brain. It can also weaken the walls of blood vessels that provide nerves with oxygen and the nutrients they need to function.
Together, this disrupts the signals that pass between the central nervous system, which consists of the brain and spinal cord, and the rest of the body.
The longer a person has diabetes, the greater the likelihood of their receiving a diagnosis of diabetic neuropathy.
The risk also increases in people who:
- have overweight or obesity
- have high blood pressure
- have high cholesterol
- have advanced kidney disease
- drink alcohol frequently
If a person with diabetes is able to keep the condition under control, they will reduce their risk of developing diabetic neuropathy.
A general practitioner, endocrinologist, or podiatrist may diagnose and treat diabetic neuropathy. They may also refer a person to a neurologist for further testing if necessary.
“Most cases of diabetic neuropathy are diagnosed by taking a good history and performing a thorough physical exam,” said Dr. Minisha Sood, an endocrinologist at Lenox Hill Hospital in New York, NY.
“Referral to a neurologist for nerve testing studies is usually unnecessary, unless the presentation of the neuropathy is unusual or asymmetric, or a patient presents with weakness or sudden onset of symptoms,” Dr. Sood added.
Managing diabetes and keeping blood sugar under control is key to reducing a person’s risk of developing diabetic neuropathy.
Once diabetic neuropathy develops, it is not reversible. However, taking steps to manage diabetes may help stop neuropathy from worsening.
“If I have a patient who has diabetes, the most important thing is to get it under control,” said Dr. Rosenberg. “If a person’s diabetes is under control, that’s the best chance to keep diabetic neuropathy from getting worse.”
Some treatments may help ease symptoms of diabetic neuropathy and reduce the risks of associated complications.
Optimizing diabetes management
Keeping blood glucose levels within target range may help prevent diabetic neuropathy or stop it from getting more severe. It is also important to manage other risk factors.
“Good glucose control with lower A1C levels reduces the stresses on the nerve cells,” said Dr. Keber. “It is also important to reduce other contributing factors. Good blood pressure control, lowering of lipids, and weight reduction — these are the hallmarks of good diabetes care.”
To manage risk factors for diabetic neuropathy, a doctor may:
- recommend changes to a person’s diet, exercise routine, or other lifestyle habits
- prescribe medication to reduce blood glucose levels, blood pressure, or blood lipids
- recommend weight loss surgery for people with obesity
Weight loss surgery can lead to weight loss and lower blood glucose levels. A 2019 review found it may also reduce symptoms of peripheral neuropathy.
“There is increasing recognition that medical or surgical weight loss in those with obesity and diabetic neuropathy would help symptom burden,” said Dr. Sood.
A doctor may prescribe treatment to ease pain from diabetic neuropathy.
“Medications include several antidepressants,” said Dr. Keber.
The antidepressant duloxetine (Cymbalta) is one common treatment. Tricyclic antidepressants, such as amitriptyline (Elavil), may also reduce pain but may cause side effects.
“Gabapentin (Neurontin) and pregabalin (Lyrica) are also options,” said Dr. Keber.
Diabetic neuropathy may also cause problems with the body’s autonomic system, which controls involuntary bodily functions, such as heart rate.
Some of these issues are treatable. For example, a doctor may prescribe medication to treat blood pressure changes or slowed digestion.
Diabetic neuropathy is a leading cause of foot ulcers in people with type 2 diabetes.
Neuropathy can reduce sensation and muscle control, increasing the risk of injury. People with reduced sensation may not realize they have an injury. This in turn can lead to poor wound care.
Diabetes can also impair blood circulation, causing skin changes and poor wound healing.
These factors raise the risk of infections and ulcers in the feet, which in severe cases may require amputation to treat. Proper foot care is essential to prevent these complications.
“One of the most important things for patients to know is how to do a daily check of their feet to catch injuries and other changes to the skin,” Dr. Keber told MNT.
“Good footwear, both socks and shoes, is also important,” she added.
Scientists continue to study the causes of diabetic neuropathy and potential treatments.
“Injectable peptide treatments, which block neuropathic pain, are being investigated, as are high-frequency spinal cord stimulators,” said Dr. Sood.
A spinal cord stimulator is a device that a surgeon implants in the body. A person can use a remote control to send electrical impulses from the device to the spinal cord.
A 2020 small case series found that high-frequency spinal cord stimulation reduced pain from neuropathy.
Researchers are also investigating the role that exercise and weight loss play in treating diabetic neuropathy.
For example, some research suggests that exercise may promote nerve fiber regeneration. This could improve symptoms and outcomes in people with diabetic neuropathy, even if being physically active does not result in weight loss.
However, more studies are necessary to understand the role of exercise in preventing and treating diabetic neuropathy.
Diabetic neuropathy can cause uncomfortable and sometimes disabling symptoms.
Keeping blood glucose within target range may help prevent diabetic neuropathy and stop it from becoming more severe. Managing weight and other risk factors is also important.
If a person thinks they may have diabetic neuropathy, they should contact a doctor so that they can help them develop strategies to improve diabetes management. They may also prescribe treatments to relieve neuropathic symptoms.