– by Dr. Jenice Robinson
1. Cardinal features of diabetic autonomic neuropathy:
All parts of the body that have autonomic nerves may be affected by diabetes. In general, the degree of involvement is related to the length of time that the patient has had diabetes and how high the glucose levels have been. For any given patient, the following organ systems may be involved: Cardiovascular, gastrointestinal (including the esophagus, stomach and colon), bladder, sexual function, sweating and vision. Symptoms and signs will vary depending on which organ systems are involved.
Up to 50% of patients with longstanding diabetes have symptoms arising from the gastrointestinal tract. Diabetic patients with cardiac autonomic neuropathy may have increased risk of mortality compared to diabetic patients without cardiac autonomic neuropathy.
2. Symptoms of diabetic autonomic neuropathy may include:
Poor exercise tolerance
Dizziness with standing
Weakness with standing
Nausea and vomiting
Feeling full after eating only a small amount of food
Diarrhea with watery, frequent bowel movements
Decreased frequency of urination
Frequent urinary tract infections
Problems of dribbling urine
Erectile dysfunction (males)
Vaginal dryness and pain with intercourse (females)
Worsening night vision
3. Signs of diabetic autonomic neuropathy on examination may include:
With change to a standing from a lying down position the heart rate change is less than normal.
While the patient slowly takes deep breaths the heart rate change is less than normal.
With change to a standing position the blood pressure falls more than normal.
Decreased sweating may be evident on examination. For example, on a very warm day if the socks are very dry this likely represents decreased sweating.
4. Differential diagnosis
In most patients, the diagnosis of diabetes is known and longstanding at the time of diagnosis. If autonomic neuropathy occurs within the first five years of diabetes, then other causes for the issue should be considered by the physician.
Autonomic testing is helpful in showing the severity of the involvement of the cardiovascular system and sweating. Involvement of other organ systems may require other testing to demonstrate.
Currently the only preventative treatment for diabetic autonomic neuropathy is good control of diabetes. Once autonomic neuropathy is present, treatment is addressed at given symptoms.
If the blood pressure drops while the patient is upright (i.e., orthostatic hypotension) and this causes dizziness or poor exercise tolerance, treatment can be directed at this symptom. Depending on the patient’s cardiac health and other health factors, treatments may include increased fluid, salt, medications to help promote salt retention and to raise blood pressure. Treatments that are not medications can also be very helpful, however. Compression garments like an abdominal binder or tightly fitting stockings compress the veins to keep the blood circulating in the arteries. Specific changes in position (for example, crossing the legs while standing) may be helpful to raise blood pressure.
If the patient has autonomic involvement of the stomach, the stomach may not be emptying properly. Improvement of diabetic control sometimes helps this; medications to improve gastric emptying may also be helpful.
Constipation is a common symptom of diabetic autonomic neuropathy, and is usually treated with high-fiber products, but may require other medications. Diarrhea may occur as well, but other causes must be evaluated, and treatment must be individualized depending on the underlying issue.
Bladder symptoms may be difficult to treat. If this is a prominent problem, often a special test of bladder function called a cystometrogram may be needed to decide on an appropriate treatment. Scheduling urination every 4 hours for some patients is a sufficient treatment. Other patients require treatment with medication.