Autonomic neuropathy

Autonomic neuropathy: an introduction

Autonomic neuropathy is nerve disorder involving the autonomic (related to the word automatic) nervous system, the system of nerves that is responsible for the function of muscles that work automatically or without our control. As many as 40% of people with diabetes may be affected by some type of autonomic neuropathy and there are a wide spectrum of organ systems that can be involved, including the cardiovascular, gastrointestinal, genitourinary, and neuroendocrine systems.

Diabetic autonomic neuropathy and its effects

Organ system

Description

Cardiovascular
  • Hypotension (postural and post-prandial)
  • Tachycardia
  • Heart attack
Gastrointestinal
  • Constipation
  • Diarrhea
  • Disorders affecting esophagus
Genitourinary
  • Bladder dysfunction
  • Sexual dysfunction
Neuroendocrine
  • Reduced or delayed hormonal secretion (glucagon, epinephrine)
Ocular
  • Abnormal pupil function
Sudomotor
  • Abnormal function of sweat glands

Various factors contribute to risk for autonomic neuropathy. Uncontrolled blood sugar appears to be the most important factor in development of this type of nerve disorder. So keeping your blood sugar within the recommended target range is important. In the National Institutes of Health (NIH)-funded Diabetes Control and Complications Trial (DCCT) intensive control of blood glucose with insulin by people with type 1 diabetes resulted in a reduction in cardiovascular autonomic neuropathy by more than 50%.1

Other factors that contribute to development of autonomic neuropathy include elevated triglyceride levels (triglyceride is a type of lipid, like cholesterol, that circulates in blood), being overweight or obese, smoking, and high blood pressure.1

The good news about diabetic neuropathy is that you can do a lot to lower your risk. First and foremost, control your blood sugar. But don’t stop there. You can make some other important healthy lifestyle changes that will lower your risk for neuropathy and other diabetes complications, including quitting smoking (if you smoke), losing excess weight and keeping it off, keeping your blood pressure and lipids under control, getting regular exercise of moderate intensity, and adopting an energy-appropriate, and nutrient-dense eating pattern. A healthy eating pattern should be based on recommendations for the general public in the US Department of Agriculture’s Dietary Guidelines for American, 2010 and should include a high intake of fruits, vegetables, and dietary fiber and a low intake of total fat, saturated fat, and added sugars.

For example, when it comes to carbohydrates, you should choose whole grains, legumes (peas and beans), vegetables, and fruits (especially those high in dietary fiber). For protein, animal- and plant-based source can be part of a healthy eating plan. However, some animal-based protein sources contain saturated fat, so low-fat, non-fat, or lean sources should be selected. For fats, monounsaturated and polyunsaturated fats, such as those found in seafood, nuts, seeds, and oils should be selected.2

Reducing risk for autonomic neuropathy

Keep blood sugar under control
Maintain normal triglycerides levels
Loose weight and keep it off
Quit smoking
Keep your blood pressure under control

Cardiovascular autonomic neuropathy

Damage to the autonomic nerves that control the heart and other parts of the cardiovascular system can result in problems, including tachycardia (an abnormally rapid heart rate), exercise intolerance (an inability of the heart to increase activity in response to exercise), extremely low blood pressure (hypotension), heart attack, kidney disease, and stroke.1

Gastrointestinal autonomic neuropathy

Damage to the autonomic nerves that control the gastrointestinal tract, including the stomach and intestines, is common. The movement of food through the gastrointestinal tract, from the esophagus to the stomach and through the intestines, relies on carefully timed contraction and relaxation of these organs. This timing is controlled by autonomic nerves.

Almost 25% of people with diabetes experience a disorder of the autonomic nerves affecting the stomach called gastroparesis, a condition of delayed emptying in which food remains in the stomach too long. This can result in erratic and difficult-to-control blood glucose. Other gastrointestinal disorders linked to autonomic nerve damage include esophageal disorders (retrosternal pain and “heartburn”), constipation, anorexia, diarrhea with frequent bowel movements, bowel incontinence, and abnormal growth of bacteria in the large intestine. Drug treatments are available for most of these conditions, including gastroparesis (metocloprimide) and bacterial overgrowth (antibiotics), and constipation (stool softeners). Additionally, changes in food choices, and occasionally, surgery may be useful in treatment of gastroparesis.1

Genitourinary autonomic neuropathy

Diabetes can result in damage to the autonomic nerves that control the bladder and sexual organs (organs of the genitourninary system). Urinary incontinence (inability to keep from leaking urine) affects people with type 1 diabetes more commonly than those with type 2 diabetes. One study found that 20% of men and 38% of women with type 1 diabetes experienced this problem. Other bladder problems that result from autonomic nerve damage include decreased ability to sense a full bladder (leading to infrequent urination), incomplete emptying, and poor urinary stream. These problem, in turn, can lead to increased risk for urinary tract infections. Common sexual problems linked to autonomic nerve damage include, in men, retrograde ejaculation and erectile dysfunction, and, in women, decreased libido and reduction in vaginal lubrication.1

Treatment approaches to bladder problems include behavioral interventions (strict adherence to a urination schedule). Drug treatments are available for urinary incontinence and other bladder problems. Treatment of sexual problems depends on the nature of the problem and may include vaginal lubricants and estrogen for problems affecting women and various drug treatments for men, including antihistamine for retrograde ejaculation and phosphodiesterase type 5 inhibitor (eg, Viagra [sildenafil citrate], Cialis [tadalafil] ) therapy for erectile dysfunction1

Other forms of autonomic neuropathy

Other forms of autonomic nerve disorders that affect people with diabetes include:

  • Sweating abnormalities (one type occurs in response to certain foods, including cheeses)
  • Abnormal pupil function
  • Changes in nerve function resulting in hormonal changes that occur due to low blood glucose (reduced production of the hormones glucagon and epinephrine)
Written by: Jonathan Simmons | Last reviewed: May 2014.
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