DIABETIC NEUROPATHY: SYMPTOMS, CAUSES AND TREATMENT - GEOGRAFÍA - 2025

The diabetic neuropathy is a type of nerve damage that occurs by the existence of diabetes, a disease characterized by high levels of blood sugar. These elevated glucose levels affect nerve fibers throughout the body, but the most commonly damaged nerves are in the legs and feet.

Diabetic neuropathy is considered the most common complication of diabetes mellitus. It affects approximately 50% of patients with type 1 diabetes (autoimmune causes, presenting from youth) and type 2 (due to insulin resistance, more common after 40 years).

Its symptoms vary depending on the severity of the condition and the type of diabetic neuropathy it is. It is normally manifested by a wide variety of sensory, motor and autonomic symptoms that greatly affect the quality of life of the patient.

However, the secondary consequences of untreated diabetic neuropathy can be even more troublesome. For example: ulcers, cardiac arrhythmias or falls, which can lead to fractures, amputations and even death.

Being a complication of diabetes, it is possible to prevent or stop the progress of diabetic neuropathy. The essential thing is for this is the strict compliance with the treatment and the rigorous control of blood glucose levels.

Definition of diabetic neuropathy

Neuropathies generally consist of a progressive loss of function of nerve fibers.

The nerve fibers are responsible for transmitting messages between the brain and any other part of our body, making you move, feel, see and hear. They also send signals that we are not aware of that come from the heart, lungs, or digestive system.

One of the most widely accepted definitions is that diabetic neuropathy consists of "the presence of symptoms and / or signs of dysfunction of certain nerve fibers in people with diabetes once other causes have been excluded." (Boulton & Malik, 1998)

In type 1 diabetes mellitus, symptoms of neuropathy begin to appear after several years of long-term and chronic hyperglycemia (high glucose levels).

While in patients with type 2 diabetes, it can already occur after only a few years of poor glycemic control. Even newly diagnosed type 2 diabetes patients are likely to already have diabetic neuropathy without knowing it.

Prevalence

In the United States, a 1993 study found that 47% of patients with diabetes had some peripheral neuropathy (that is, involving peripheral nerves affecting the hands and feet). Furthermore, it seemed to already be present in 7.5% of patients at the time they were diagnosed with diabetes.

This condition affects both sexes equally. However, it appears that men with type 2 diabetes mellitus tend to develop diabetic neuropathy earlier than women. Although neuropathic pain appears to be more disabling for women than for men.

Regarding age, this disease can appear at any time in life. However, it is more likely at an older age. This risk increases markedly the more severe and lasting diabetes is.

Causes

As the name suggests, diabetic neuropathy is caused by poorly controlled or untreated diabetes mellitus. Diabetes mellitus is a disease that causes glucose (sugar) levels to be very high in the blood.

It seems that this, together with the interaction between nerves and blood vessels, and other risk factors, predispose the patient to develop neuropathy.

How continuous exposure to high glucose levels causes nerve damage is still being investigated. Also, the causes seem to vary according to the different types of diabetic neuropathy (which you'll see later).

Factors that increase the chance of developing diabetic neuropathy are:

Metabolic factors

Long-term diabetes that has not been properly treated causes high blood glucose. High blood fat levels and low insulin levels also play a role; a hormone produced by the pancreas that regulates the amount of glucose.

Neurovascular factors

High sugar levels interfere with the function of the nerves to transmit sensory and motor signals. In addition, it deteriorates the walls of the smallest blood vessels (capillaries), which are responsible for carrying oxygen and nutrients to the nerve fibers.

Autoimmune factors

They can cause inflammation of the nerves. In particular, what happens is that the immune system, which is normally responsible for protecting our body, mistakenly attacks the nerves as if they were a foreign element.

Hereditary or genetic factors

If the individual has a family history of neuropathy or diabetes, they will be more prone to developing this condition.

Alterations in the functioning of the kidneys

Diabetes can damage kidney function. This increases the amount of toxins in the blood, which contributes to the deterioration of nerve fibers.

Lifestyle

If, together with other factors already mentioned, the patient consumes alcohol and tobacco, they will be more likely to damage their nerves and blood vessels. In fact, smoking narrows and hardens the arteries, decreasing blood flow to the legs and feet.

Lifestyle includes the most important risk factor for any complication of diabetes: inadequate control of blood sugar levels. If the diabetic does not continually keep his glucose level in check, diabetic neuropathy (among many other complications) is likely to develop.

Likewise, having diabetes for a longer time has an influence, especially if glucose levels are not well controlled.

On the other hand, being overweight increases the risk of developing diabetic neuropathy. Mainly if the body mass index exceeds 24 points.

Types of diabetic neuropathy and their symptoms

Depending on the nerves that are affected, there are different types of diabetic neuropathy. Each has characteristic symptoms. These generally range from numbness and pain in the limbs to problems with the digestive system, urinary tract, blood vessels, or heart.

Depending on the case, the symptoms can be mild and even imperceptible, while in others, diabetic neuropathy can be very painful and even lead to death. Most manifestations develop slowly and may not be bothersome until damage has begun.

There are four main types of diabetic neuropathy:

-Peripheral neuropathy

It is the most common type of diabetic neuropathy. It is characterized by an involvement of the peripheral nerves, so that the feet and legs are first damaged; and later, the hands and arms.

Its signs and symptoms are usually accentuated at night, and include:

- Numbness of the affected areas, in addition to a decrease in sensitivity to pain and changes in temperature.

- Tingling, burning, sharp pains and / or cramps in the affected joints.

- There may be an increase in tactile sensitivity. For example, these individuals may even be bothered by the weight of the sheet on their feet or legs.

- Serious foot problems such as infections, ulcers, deformities, pain in bones and joints.

- Muscular weakness.

- Progressive loss of reflexes, balance and coordination.

-Autonomic neuropathy

Diabetes can affect the autonomic nervous system. Your nerve fibers are what control your heart, lungs, stomach and intestines, bladder, sex organs, and eyes.

Your symptoms are:

- Diarrhea, constipation or the combination of both at different times.

- Gastroparesis or delay in stomach emptying due to abnormal intestinal motility. This causes loss of appetite, early satiety, bloating, nausea, and even vomiting.

- Infections in the urinary tract, urinary incontinence and other disorders in the bladder (such as retention).

- Difficulty swallowing.

- Increase or decrease in sweating.

- Problems regulating body temperature.

- Sexual difficulties such as erectile dysfunction in men, and vaginal dryness in women.

- Dizziness or fainting when changing position (such as standing up suddenly). They occur due to the inability of the body to adapt blood pressure and heart rate, which causes a significant decrease in blood pressure.

- Asymptomatic hypoglycemia, that is, patients no longer detect the alarm symptoms that indicate that they have very low blood sugar levels.

- Increased heart rate while at rest.

- The pupils take time to adapt to the change in light (from light to dark or vice versa).

-Proximal neuropathy or diabetic amyotrophy

Also called femoral neuropathy, this type of diabetic neuropathy affects the nerves in the thighs, hips, buttocks, or legs. It is more common in patients with type 2 diabetes mellitus and the elderly.

Usually the symptoms affect only one side of the body, but it can also occur on both sides at the same time (in this case, it is called symmetric). Over time, this condition tends to improve, although symptoms may be accentuated before improving. The typical manifestations are:

- Sudden and severe pain in the hip, thigh or buttocks.

- The thigh muscles are often atrophied or severely weakened.

- Weightloss.

- abdominal swelling.

- Difficulty getting up when sitting.

-Focal neuropathy or mononeuropathy

In this case, the damage is focused on a specific nerve. It is more common in older adults and usually appears suddenly.

The affected nerve can be found in the face, torso or legs. Although it can actually happen to any nerve in the body. It is characterized by intense pain. However, its symptoms do not cause long-term problems and tend to decrease and disappear within a few weeks or months.

The specific manifestations depend on the affected nerve; and depending on the location they could be:

- Pain in the eye, accompanied by difficulties to focus, or double vision.

- Bell's palsy or peripheral facial palsy, which consists of damage to the nerves of the face that cause the paralysis of one side of the face.

- Pain in the chest or abdomen.

- Pain in the front of the thigh.

- Pain in the back or pelvis.

- Pain or loss of sensation in one foot.

Sometimes this type of diabetic neuropathy occurs due to compression of a nerve. A common example is carpal tunnel syndrome, which gradually produces tingling or numbness in the fingers or hand.

The hand feels weak, and difficulties in performing some movements with it, such as making a fist or taking small objects.

Diagnosis

In people already diagnosed with diabetes, follow-up is recommended to check if other complications have appeared, such as diabetic neuropathy.

In particular, a comprehensive foot exam every year is highly recommended for peripheral neuropathy. Either by a doctor or podiatrist, who must also check for sores, cracks, corns, blisters, condition of the bones and joints.

On the other hand, neuropathy symptoms may be experienced, but the patient does not know what they are due to, and is later found on tests to have diabetic neuropathy.

To detect it, health professionals will first take into account the symptoms, and the patient's medical history. Then a physical exam will be necessary.

This will check muscle tone, reflexes, strength, sensitivity to touch and changes in position, temperature and vibration. The doctor may also check your blood pressure and heart rate.

The most commonly used tests to diagnose neuropathy are:

- Monofilament test: sensitivity to touch is examined through a soft nylon fiber, similar to the bristles of hairbrushes. Sometimes it is checked through a pin, giving small pricks.

If the patient cannot feel the pressure of the prick, they have lost sensation and are at risk of developing ulcers on the affected foot.

- Quantitative sensory tests: how the patient responds to changes in temperature or more or less intense vibrations is checked.

- Nerve conduction studies: these are used to determine the type and extent of nerve damage, as well as how fast electrical signals travel. It is useful in diagnosing carpal tunnel syndrome.

- Electromyography: used to measure the electrical discharges that muscles produce.

- Heart Rate: This examines how the heart responds to deep breathing and changes in blood pressure and posture.

- Ultrasound: it is the use of sound waves to create an image of the internal organs. It can be done to examine the bladder and urinary tract or other organs that may be affected by diabetic neuropathy.

Treatment

There is no specific treatment for diabetic neuropathy. First of all, the patient must strictly comply with the established treatment for diabetes, as well as its control and monitoring.

Patient education is essential so that they understand what their condition is about, the consequences it has for their health, and the improvements that can be achieved by following treatment.

Treatment for diabetic neuropathy is focused on relieving pain, slowing down the progression of the disease, recovering possible altered functions and avoiding complications.

Control of diet and nutrition is essential to improve complications of diabetes. These patients should follow a diet that lowers blood glucose, minimizing extreme fluctuations.

In addition to healthy eating, it is recommended that they be as active as possible. Thus, sugar levels are within normal ranges, which prevents or slows the progression of diabetic neuropathy and even improves its symptoms.

At the same time, you will be avoiding being overweight; another risk factor for developing diabetic neuropathy.

It is also important to prevent or reduce disease, control and monitor blood pressure. Like giving up bad habits like smoking or drinking alcohol (or reducing their consumption to a minimum).

Medicines

In order to reduce pain, your healthcare professional may prescribe medications. However, these are not as effective worldwide and can have bothersome side effects.

Some of the most used are antidepressants, which prevent the brain from interpreting certain stimuli as painful. For example, desipramine, imipramine, and amitriptyline. Serotonin and norepinephrine inhibitor antidepressants, such as duloxetine, seem to eliminate pain with fewer side effects than the above.

Other drugs used are anticonvulsants, which are commonly used to treat epilepsy. Although they have been found to be effective for nerve pain, like gabapentin, pregabalin, and carbamazepine.

Physiotherapy

Physiotherapy is a good option if you want to relieve pain and maintain adequate mobility, as well as work on balance, strength and coordination.

As mentioned, the care and examination of the feet once a year is essential.

In certain types of diabetic neuropathy, patients may not have sensation in this area; developing ulcers and lesions. Also, they are more likely to have any condition in that part of their body.

Therefore, they must trim their toenails correctly and carefully, maintain maximum hygiene, and wear appropriate shoes.

Treatment of associated complications

On the other hand, the doctor must treat the associated complications. For example, gastroparesis (through diet changes, increasing the frequency of meals and reducing the amount), urinary problems (with medications and behavioral techniques such as timed urination), or sexual dysfunctions (drugs in men and lubricants in women).

References

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4. Nerve Damage (Diabetic Neuropathies). (sf). Retrieved on November 10, 2016, from The National Institute of Diabetes and Digestive and Kidney Diseases.
5. NERVES (NEUROPATHY). (sf). Retrieved on November 10, 2016, from Diabetes UK.
6. Pirart J. (1978). Diabetes mellitus and its degenerative complication: a prospective study of 4,400 patient observed between 1947 and 1973. Diabetes Care, 1: 168-188.
7. Quan, D. (2016, July 6). Diabetic Neuropathy. Obtained from Medscape.