Causes and Risk Factors of Diabetic Neuropathy

Diabetic neuropathy is a complication of long-term diabetes mellitus, especially when blood sugar is not well controlled. It is caused by nerve damage that can occur with type 1 diabetes or type 2 diabetes. 

This article describes the risk factors, types, and causes of diabetic neuropathy. 

Common Types and Causes 

Diabetic neuropathy affects the peripheral nervous system and includes four types of nerve damage. They can begin at different times—and some people with diabetes might experience a few effects of diabetic neuropathy rather than all of them.  

These include: 

• Peripheral neuropathy, which involves the small nerves in the hands and feet, is usually approximately equal on both sides of the body
• Proximal neuropathy, which affects nerves that control large muscles in the body, such as in the thighs and shoulders, is not usually symmetrical
• Autonomic neuropathy, which causes symptoms that interfere with digestion, urination, blood pressure, and heart function
• Focal neuropathy, which affects the control of one area of the body, like the arm, and not necessarily both sides of the body 

Diabetic neuropathy affects sensory nerves and motor nerves, causing pain, loss of sensation, and muscle weakness.

How Nerve Damage Happens 

Neuropathy in diabetes occurs due to both demyelination and axonal injury. Demyelination is damage to the protective fat layer (myelin) surrounding the nerves. Axonal injury is the destruction of the nerve itself.

Several factors are associated with diabetic neuropathy:

• Microvascular compromise: The small blood vessels that supply oxygen-rich blood to the nerves can become narrow or completely blocked due to vascular damage from diabetes.
• Inflammation: Areas of nerve damage in diabetic neuropathy often have inflammatory cells.
• Metabolic abnormalities: Chemical alterations lead to the production of sugars and proteins that have been found to injure nerves in diabetic neuropathy.

All these factors prevent the nerves from getting the nutrients they need to function properly and survive. Over time, the nerves degenerate. Eventually, the muscles supplied by these nerves can atrophy (wither away).

Genetics 

Research shows that long-term metabolic changes of diabetes can affect how certain genes are expressed. With these changes, some proteins needed to maintain healthy nerves are no longer produced. This change in gene expression has been associated with diabetic neuropathy.

Researchers are looking at potential ways to use this information to develop treatments that could slow down the progression of diabetic neuropathy. 

Cardiovascular 

Diabetes causes vascular changes in small blood vessels throughout the body. This causes a decrease in blood supply to structures like the nerves, eyes, and kidneys.

Low blood supply means that these tissues don’t get the oxygen and nutrients that they need. This eventually leads to cell and tissue degeneration, including the type of nerve degeneration that contributes to diabetic neuropathy. 

Additionally, the cardiovascular system is affected by autonomic diabetic neuropathy. This can lead to irregularities in blood pressure regulation and heart rate, which raise your risk of serious complications, such as heart disease and stroke.

Lifestyle and Risk Factors

Many lifestyle factors can increase the risk of diabetic neuropathy. Uncontrolled diabetes can accelerate the development of diabetic neuropathy.

Lifestyle factors that may cause nerve damage, inflammation, or vascular problems can compound the risk of developing neuropathy and experiencing serious nerve damage that adds to the damage of diabetic neuropathy. 

Factors that can increase the risk of neuropathy are:

• Irregular blood sugar or high blood sugar 
• Excess alcohol consumption
• Smoking
• Malnutrition (not getting enough calories, vitamins, minerals, protein, fat, and carbohydrates in the diet)
• Taking medication that can cause neuropathy, such as chemotherapy 
• Untreated health issues, like lung disease 
• Environmental toxin exposure

If you have diabetes, you might develop diabetic neuropathy even if you control your blood sugar levels. But you can lower the risk by adopting some consistent lifestyle strategies. 

Ways to reduce the risk and severity of diabetic neuropathy include:

• Check your blood sugar on a schedule determined by your healthcare provider.
• Follow a diet and medication plan to keep your blood sugar at healthy and stable levels.
• Maintain a diet with adequate nutrients, such as carbohydrates, protein, fat, vitamins, and minerals.
• Keep up with your visits to your healthcare provider and get medical problems checked out and treated.
• Do not smoke or drink alcohol.

Summary 

Diabetic neuropathy can be a complication of uncontrolled type 1 or type 2 diabetes. The nerve damage can affect peripheral nerves, proximal nerves, and autonomic nerves, and it can cause focal areas of nerve damage as well. Sensory and motor nerves are impacted by diabetic neuropathy.

Over time, this condition develops due to diabetes-induced vascular disease, inflammation, and metabolic changes. Some risk factors, including poorly controlled blood sugars, smoking, alcohol, and neurotoxic medication exposure, can compound the risk of developing diabetic neuropathy.

A Word From Verywell 

If you have been diagnosed with diabetes, it’s important for you to be familiar with the potential complications.

Anyone who has diabetes can develop diabetic neuropathy, but poorly controlled blood sugars, as well as other factors that can contribute to any type of neuropathy (like alcoholic neuropathy), can increase the likelihood of developing severe effects of diabetic neuropathy.

Talk to your healthcare provider about what you can do to reduce your risk of diabetic neuropathy.