Dysautonomia commonly develops as a complication of a primary illness or is seen in patients with multiple disorders.  These scenarios add a layer of complexity to a patient’s diagnostic journey, as well as their treatment plan.  When one of those illnesses is an eating disorder, the complexities can be significantly magnified.

Eating disorders, which include bulimia nervosa and anorexia nervosa, are defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM) as follows:
"Feeding and eating disorders are characterized by a persistent disturbance of eating or eating-related behavior that results in the altered consumption or absorption of food and that significantly impairs physical health or psychosocial functioning."

The lifetime prevalence estimates for bulimia nervosa and anorexia nervosa in US adults are 1.0% and 0.6%, respectively. [1] Members of the dysautonomia community are most likely some of the people additionally affected by these severe conditions.

In wading through the medical literature on eating disorders and dysautonomia, several parallels emerged. These parallels can be seen in the demographics of the patient population, as well as in the symptoms both disorders can demonstrate.  For instance, both anorexia nervosa [1] and Postural Orthostatic Tachycardia Syndrome (POTS), a form of dysautonomia, are more commonly observed in women and adolescent girls. [2].  Also, anxiety and depression are common in both dysautonomia [3] and eating disorder patients. [1]

Further, POTS and other forms of orthostatic intolerance can cause gastrointestinal symptoms, such as nausea and vomiting and severe POTS may interfere with eating. [4] [5] A POTS patient and an eating disorder patient may both have disrupted eating patterns, but the underlying causes and appropriate treatments are very different. Although I did not find specific evidence in the literature of such symptoms misattributed to eating disorders, it is not uncommon for a misdiagnosis of anxiety or other psychiatric illness attributed to POTS. [5]

There is also evidence that eating disorders, particularly anorexia nervosa, may cause changes in cardiac function, structure, and rhythm. [6] Children with anorexia and bulimia may exhibit abnormally low blood pressure, slowed heart rates, and high heart rate variability. [7] In the abstract to a 2014 article in Clinical Autonomic Research, Takimoto, et al. reported autonomic abnormalities during tilt-table testing in study participants with anorexia nervosa. [8] Similarly, POTS and other forms of dysautonomia, display hallmark symptoms of high heart rates, abnormal rhythms, and erratic blood pressures. [13] And the irregular response of the autonomic nervous system during the tilt table test is one of the most recognized diagnostic criteria used to confirm a POTS diagnosis.

There are conflicting views in the literature about the extent to which cardiac complications explain the fatality rates in anorexia and bulimia and whether such changes are reversible. [7] [9] Further research into these questions is needed, but what is certain is that eating disorders can be dangerous and require serious attention.  While most forms of dysautonomia are chronic illnesses, they are not considered life-threatening on their own; rather, they are seriously life-altering and oft-times debilitating. Dysautonomia also requires serious attention and treatment.

Stewart writes that it is essential to distinguish between eating disorders and POTS, noting that anorexia nervosa can cause “POTS-like” orthostatic intolerance in its early stages and young women referred for treatment for POTS symptoms may be underweight.[8]  The similarities in patient demographics and overlap in symptoms between eating disorders and POTS have the potential to complicate the diagnostic picture further.

Patients can have both conditions, of course, which may present additional diagnostic and treatment challenges. An untreated eating disorder might worsen pre-existing orthostatic intolerance. Since poorly managed orthostatic intolerance can cause limitations in many areas of life, such conditions, if unrecognized, could conceivably pose an additional challenge for eating disorder patients in achieving specific functional goals as part of treatment.

There remains much to learn about both eating disorders and dysautonomia. Both can have a profound and long-lasting impact on a person’s life and health at an important point in that person’s development.  Accurate diagnosis and appropriate treatment are vital.

It is important to note that although the focus of this article was on anorexia, bulimia and largely POTS, there are many other eating disorders and dysautonomias. Further, these conditions can occur in people of any gender and at any stage of life.  If you or someone you know is dealing with an eating disorder or dysautonomia, please consult a qualified medical professional without delay.

Bibliography

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