Diabetic Neuropathy: An Overview Of Risk Factors & Prevention
An Overview of Diabetic Neuropathy
Diabetic neuropathy is a diabetes-related complication that can develop when chronically elevated blood sugar levels cause damage to the body’s nerves. Diabetic neuropathy can affect nerves in many different areas of the body, but it most commonly damages the nerves of the legs and feet.
Up to 50 percent of patients with diabetes may suffer from diabetic neuropathy. However, measures such as maintaining a healthy lifestyle and keeping tight control of blood glucose levels may prevent or slow the progression of diabetic neuropathy.
Symptoms of Diabetic Neuropathy
The symptoms of diabetic neuropathy are variable in type and severity, and they generally correspond with the types of damaged nerves. Symptoms usually develop gradually, and they may be mild at first. Patients may not realize they have a nerve problem until significant nerve damage has occurred.
Pain and numbness are common with diabetic neuropathy, and they can even be severe enough to lead to significant disability. Diabetic neuropathy may also affect the nerves of the digestive system, cardiovascular system, and genitourinary system, causing a myriad of system-specific symptoms.
Types of Diabetic Neuropathy
Diabetic neuropathy is classified into four types, based on which nerves have damage. Each type of diabetic neuropathy has specific characteristics, as detailed below.
1. Peripheral Neuropathy (Distal Symmetric Peripheral Neuropathy)
Peripheral neuropathy is the most common type of diabetic neuropathy. Peripheral neuropathy classically impacts the feet and legs initially, and it may later affect the hands and arms.
Other hallmarks of peripheral neuropathy include:
- Worsening of symptoms at night
- The sensation of burning, tingling, or numbness
- Reduced sensation or loss of the ability to distinguish between temperatures
- Cramping or sharp pains
- Heightened sensitivity to touch, even light tough (i.e., a bedsheet)
- Complications related to diabetes and feet, including ulcers, infections, or pain of the bones or joints
2. Autonomic Neuropathy
Autonomic neuropathy is caused by damage to the nerves involved in controlling processes related to the cardiovascular system, digestive system, genitourinary system, reproductive system, and visual system.
Hallmarks of autonomic neuropathy may include:
- The inability to perceive blood sugar decreases (a condition known as “hypoglycemia unawareness”)
- Difficulties with bowel or bladder function
- A condition known as “gastroparesis,” in which the stomach empties very slowly, potentially leading to nausea, vomiting, or appetite decrease
- Difficulties with adjusting one’s vision from a light to dark setting
- Lessened responsiveness in sexual settings
3. Proximal Neuropathy (Diabetic Polyradiculopathy)
In proximal neuropathy (also known as “diabetic amyotrophy”) the more centrally located nerves of the legs, thighs, hips, buttocks, abdominal region, or chest region are damaged. Unlike peripheral neuropathy, patients initially tend to experience symptoms more on one side of the body, but they may eventually have symptoms on both sides.
Hallmarks of proximal neuropathy may include:
- Stomach, buttock, hip, or thigh pain that is severe
- Muscle weakening and atrophying, particularly of the thighs
- Challenges with position changes, such as going from sitting to standing
4. Mononeuropathy (Focal Neuropathy)
In mononeuropathy, damage occurs in one specific nerve. Both cranial and peripheral nerves can be affected by mononeuropathy.
Hallmarks of mononeuropathy may include:
- Visual changes, such as “seeing double” or difficulty focusing
- An aching sensation behind an eye
- One-sided facial paralysis (such as Bell’s palsy)
- Tingling or numbness of the fingers or hands that spares the fifth digit (“pinkie finger”)
- Hand weakness with a notable increase in clumsiness or dropped items
Causes of Diabetic Neuropathy
According to medical researchers, diabetic neuropathy is associated with chronically elevated blood sugar levels that damage the nerves and reduce their ability to transmit nerve signals. Chronically elevated blood sugar levels can also damage the small blood vessels that provide the body’s nerves with needed nutrients and oxygen. However, the exact cause of each type of neuropathy remains unknown.
Risk Factors for Diabetic Neuropathy
Nerve damage can occur in anyone with diabetes; however, these risk factors increase the likelihood of developing diabetic neuropathy:
- Inadequate control of blood sugar levels
- A longer length of time with a diabetes diagnosis
- Having diabetic-related kidney disease
- Being overweight with a body mass index (BMI) of 25 or higher
Complications of Diabetic Neuropathy
A variety of complications can stem from diabetic neuropathy, including the following:
- Hypoglycemia unawareness: Autonomic neuropathy can impair a patient’s ability to perceive the symptoms associated with a low blood sugar level (less than 70mg/dL) such as increased heart rate, sweating, or shaking.
- Amputation: Peripheral neuropathy can increase a patient’s likelihood of developing an infected diabetic foot ulcer, a condition that sometimes leads to toe, foot, or lower leg amputations.
- Urinary concerns: Autonomic neuropathy can damage the nerves of the bladder, decreasing the patient’s ability to fully empty the bladder and an increased risk of subsequent urinary tract infections. Similarly, when the nerves of the bladder are damaged, patients lose the ability to perceive the need to urinate, and they may also lose control of their ability to release urine, a condition known as “incontinence.”
- Dramatic blood pressure fluctuations: When the nerves of the cardiovascular system are damaged by autonomic neuropathy, the body can no longer make quick blood pressure adjustments. This means that patients may have rapid blood pressure drops with positional changes such as rising from a seated position, and these drops may cause lightheadedness, dizziness, or fainting.
- Digestive concerns: In addition to slowed stomach emptying (gastroparesis), autonomic neuropathy of the digestive system may lead to bowel dysfunction such as constipation or diarrhea.
- Sexual concerns: When autonomic neuropathy strikes the sexual organs, men can have difficulty achieving or maintain erections, and women can have difficulty with sexual arousal and lubrication responses.
- Temperature management: When diabetic neuropathy affects the sweat glands, causing either an increased or decreased sweat response, patients may experience difficulties properly controlling their body temperature.
Preventing Diabetic Neuropathy
Diabetic neuropathy and its complications may be prevented or delayed with careful attention to the following:
Blood Sugar Management
By tightly controlling their blood glucose levels, patients can minimize the amount of harm to the nerves and, therefore, reduce their chances of developing diabetic neuropathy. To track how well blood sugar is being controlled, clinicians use a test called a hemoglobin A1C (or “A1C”), which gives information about a patient’s average blood sugar level over the past two to three months. The American Diabetes Association recommends that patients with diabetes receive an A1C test at least twice a year, with an A1C target of less than 7 percent.
Routine Foot Care
The downstream consequences of diabetic neuropathy of the feet, such as diabetic foot ulcers and amputations, may be largely prevented through routine monitoring. The American Diabetes Association recommends a diabetic foot exam once annually—this can be conducted by a podiatric doctor (foot and ankle specialist).
Diabetic patients should also adhere to the following home foot care guidelines:
- Patients should assess their feet daily, examining for cuts, cracks, redness, swelling, bruising, or blisters.
- Patients should use a mirror or enlist a friend or family member to examine the parts of the foot that they cannot visualize.
- Patients should wash their feet daily using mild soap and lukewarm water.
- Patients should avoid soaking their feet.
- Patients should carefully dry their feet, with special attention to the areas between their toes.
- Patients should moisturize their feet to prevent cracking, but take care to avoid getting lotion between the toes because this could lead to a fungal infection.
- Patients should keep their toenails carefully trimmed straight across, and file them to avoid the development of sharp areas.
- Patients should wear dry socks, preferably made with a fabric that is cotton or moisture-wicking. Socks should not have thick seams or tight areas that could cause friction or skin breakdown.
- Patients should always wear well-fitting shoes or slippers in order to protect their feet. A podiatry specialist can help patients identify which shoes are the most appropriate to prevent the development of ulcers or other abnormalities, such as calluses or corns. Patients with Medicare may be eligible for at least one pair of diabetic shoes annually.
Avoidance of Smoking
Patients may reduce their chances of developing peripheral neuropathy by reducing or eliminating smoking. Smoking can impair the blood circulation of the legs and feet, which damages the peripheral nerves and makes it more difficult for the body to heal.
When To See A Doctor for Diabetic Neuropathy
The American Diabetes Association recommends screening for diabetic neuropathy in the following scenarios:
- Immediately after an initial diagnosis of Type 2 diabetes, with annual screening thereafter
- Five years after an initial diagnosis of Type 1 diabetes, with annual screening thereafter
Additionally, patients should contact a medical professional immediately for evaluation of the following:
- Cuts or sores that are not healing or appear infected
- Tingling, burning, pain, or weakness of the feet or hands that interferes with daily functioning
- Functional changes related to the urinary, digestive, or reproductive systems
- Fainting or dizziness