From the Guidelines
Autonomic dysregulation, also known as autonomic nervous system dysfunction, refers to any abnormal function of the autonomic nervous system, encompassing a range of disorders including neurogenic orthostatic hypotension, reflex syncope, and postural orthostatic tachycardia syndrome (POTS) 1.
Key Points
- Autonomic dysregulation can manifest as various symptoms, including resting tachycardia, orthostatic hypotension, gastroparesis, constipation, diarrhea, fecal incontinence, erectile dysfunction, neurogenic bladder, and sudomotor dysfunction with either increased or decreased sweating 1.
- Cardiovascular autonomic neuropathy (CAN) is a specific type of autonomic dysregulation associated with mortality independently of other cardiovascular risk factors, and can be detected by decreased heart rate variability with deep breathing or resting tachycardia and orthostatic hypotension in advanced stages 1.
- The prevalence of confirmed CAN is around 20%, increasing up to 65% with age and diabetes duration, and is a risk marker of mortality and cardiovascular morbidity 1.
Diagnosis and Management
- Diagnosis of autonomic dysregulation involves assessing symptoms and signs, such as orthostatic intolerance, syncope, exercise intolerance, and gastrointestinal or genitourinary symptoms, and may require further testing like cardiovascular autonomic testing, sweat testing, or urodynamic studies 1.
- Management of autonomic dysregulation focuses on alleviating symptoms, maintaining blood pressure within a normal range, and providing organ-specific support, with treatment approaches varying depending on the underlying cause and affected organs 1.
Importance of Early Detection
- Early detection and assessment of autonomic dysregulation are crucial for preventing secondary organ damage and improving outcomes, particularly in patients with diabetes or other high-risk conditions 1.
- Annual assessment for autonomic neuropathy is recommended for individuals with type 1 diabetes for 5 years or more and all individuals with type 2 diabetes 1.
From the Research
Definition and Causes of Autonomic Dysregulation
Autonomic dysregulation, also known as autonomic nervous system dysfunction, refers to a condition where the autonomic nervous system (ANS) fails to function properly, leading to various symptoms and disorders. The ANS is responsible for regulating involuntary functions, such as heart rate, blood pressure, and digestion.
Symptoms and Related Conditions
Some common symptoms and related conditions of autonomic dysregulation include:
- Orthostatic hypotension (OH), which is a sudden drop in blood pressure upon standing, leading to dizziness, lightheadedness, and fainting 2, 3, 4, 5
- Orthostatic intolerance, which is the development of disabling symptoms upon assuming an upright posture, such as palpitations, tremor, and near-syncope 6
- Postural tachycardia syndrome (POTS), which is characterized by excessive orthostatic sinus tachycardia, lightheadedness, tremor, and near-syncope 6
- Supine hypertension and postprandial hypotension, which are frequent comorbidities that may exacerbate orthostatic hypotension 3
Pathophysiology
The pathophysiology of autonomic dysregulation involves:
- Sympathetic neurocirculatory failure and impaired cardiovagal activity, leading to inadequate release of norepinephrine in the vasomotor sympathetic system 3
- Hyperadrenergic activation or hypovolemia during orthostasis, which can contribute to the development of POTS 6
- Impaired baroreceptor mechanisms, which can lead to extracellular fluid volume depletion and exacerbate orthostatic hypotension 2
Treatment Options
Treatment options for autonomic dysregulation include:
- Non-pharmacologic therapies, such as increasing fluid and salt intake, venous compression methods, and avoiding large carbohydrate-rich meals 3, 5
- Pharmacologic treatments, such as midodrine, droxidopa, fludrocortisone, pyridostigmine, and atomoxetine, which can help increase blood pressure and alleviate symptoms 2, 6, 3, 4, 5