Eating disorders are associated with high use of medical resources, but often go unrecognized in medical settings. All physicians should be alert to signs and symptoms of these relatively common behavioral disorders. Patients may deny they have an eating disorder, as these conditions are associated with high levels of ambivalence towards treatment, as well as feelings of shame and stigma. 

Patients frequently present to a variety of medical specialists including pediatricians, internists, gastroenterologists, endocrinologists, gynecologists, neurologists, cardiologists, orthopedic specialists, and psychiatrists seeking help for medical or psychiatric complications of their eating behavior, whether or not they acknowledge their diagnosis. They may avoid treatments focused on normalizing their eating behavior, favoring instead medical interventions that address consequences of their behavior without altering the underlying problem. 

Eating disorders can affect all organ systems and presenting concerns are quite varied. The following Top 10 list reviews common medical presentations and laboratory values that may reflect an occult eating disorder.

1. Metabolic or electrolyte abnormalities

• Rapid weight loss may indicate anorexia nervosa and rapid weight gain may result from new onset binge eating disorder
• Hypokalemia can be a sign of regular self-induced vomiting, especially in the presence of low chloride and elevated bicarbonate. Laxative abuse may also lead to hypokalemia and can result in either metabolic acidosis or alkalosis. Diuretic abuse can result in hypokalemia and contraction alkalosis. 
• Hypoglycemia may be starvation-related in anorexia nervosa
• Hyponatremia may result from excessive water intake, a behavior often used to suppress appetite and increase satiety or to artificially inflate weight gain.
• Hypophosphatemia may be detected on initial evaluation following weight loss, although more commonly a complication of refeeding

 2. Gastrointestinal concerns

Functional gastrointestinal disorders are present in the vast majority of inpatients with eating disorders treated on specialty behavioral units. Patients may also present with excessive and disabling preoccupations or idiosyncratic ideas regarding food intolerances or bowel regimens. Delayed gastric emptying and slowed whole gut transit times are typical of anorexia nervosa and gastroparesis is also commonly present in bulimia. 

• Abdominal bloating, pain and constipation and other symptoms typical of irritable bowel syndrome are frequently associated with starvation or with binge intake of food.
• Gastrointestinal reflux disease (GERD), esophageal Mallory Weiss tears, bilateral parotid gland enlargement, dental caries and enamel erosion are all associated with self-induced vomiting. Most individuals who vomit regularly have lost the gag reflex and many can vomit spontaneously without inducing a gag. 
• Transaminitis and elevated lipase and amylase are frequent consequences of anorexia nervosa and can be associated both with both starvation and refeeding.
• Acute gastric dilatation is a rare, life threatening presenting symptom in patients with anorexia nervosa who binge eat and may cause superior mesenteric artery syndrome.
• Rectal prolapse and hemorrhoids can be complications of laxative abuse.

 3. Gynecologic and obstetric concerns

• Hypothalamic amenorrhea and infertility are common in anorexia nervosa.
• Pregnancy may be associated with poor weight gain, intrauterine growth restriction or hyperemesis gravidarum in individuals who purge by vomiting.
• Postpartum rapid weight loss due to excessive breast pumping and milk wasting has been described. 

4. Neurologic presentations

• Syncopal or presyncopal episodes and orthostasis due to fluid restriction or diuretic and laxative abuse may be presenting symptoms.
• Somatoform pain disorders especially abdominal pain complaints or headaches are common.
• Seizures may be due to hypoglycemia or to excessive water intake and resultant hyponatremia.
• Wernicke-Korsakoff’s syndrome can be a complication of refeeding in very low weight anorexia nervosa, especially when comorbid with alcohol abuse. Preventative thiamine supplementation is critically important in these cases.

 5. Cardiac presentations

• Bradycardia is often detected in anorexia nervosa and can be severe with heart rates of 30 or below and may be associated with QTc prolongation and increased risk of cardiac arrest.
• Orthostatic hypotension or tachycardia may reflect dehydration from purging or fluid restriction or from impaired vagal tone.
• A starvation cardiomyopathy and heart failure may occur in severe and chronic anorexia nervosa.
• Mitral valve prolapse due to atrophic cardiac muscle may be evident on exam.
• Arrthymias may occur due to electrolyte abnormalities or caffeine or ephedrine diet suppressant abuse.

6. Endocrine presentations

• Hypothalamic amenorrhea and infertility, as well as osteoporotic fractures are complications of anorexia nervosa. 
• Sick euthryoid labs are commonly seen in anorexia nervosa with low T3 and rT3 and ration of T4 to rT3 is elevated. TSH and T4 may be suppressed. 
• Hypercortisolemia is common in anorexia nervosa as a result of starvation related activation of the HPA axis and may contribute to bone loss and osteoporosis.
• Frequent ketoacidosis in a diabetic may reflect purging by underdosing insulin or insulin omission in order to waste calories.

7. Hematological presentations

• Anemia, leukopenia and thrombocytopenia are all seen in severe anorexia nervosa as starvation is associated with bone marrow hypocellularity and fatty infiltration.

8. Psychiatric complications

• Major depression, anxiety disorders, and substance abuse are commonly comorbid with eating disorders and tend to worsen with the severity of the eating disorder.

9. Renal presentations

• Although relatively uncommon, renal failure can be seen in cases of severe laxative and or diuretic abuse. Contraction alkalosis and dehydration may be evident. In starvation, blood urea nitrogen may be very low due to low protein intake and 24-hour creatinine clearance is often decreased and is lower for laxative abusers than for pure restrictors.

10. Opportunistic infections

• At severely low BMIs patients can present with opportunistic infections. Case reports include mycobacterial infections and aspergillosis.

SCREENING FOR AN EATING DISORDER BY PRIMARY CARE PHYSICIANS

As a primary care provider, you could be the first person to recognize and offer assistance regarding a patient’s eating and weight concerns. Although patients may not disclose information immediately, your sustained interest and concern may eventually allow your patient to admit his or her problems and accept your help.

Ask about:

• History of weight fluctuations; low weight/high weight, desired weight
• Actions taken to maintain, control, or alter weight
• Laxatives, enemas, diuretics, appetite suppressants, supplements                      
• Vomiting
• Excessive exercise
• Periods of binge eating or feeling a lack of control over food intake
• Comfort with current weight/shape
• Report of typical daily food and water intake
• Exercise habits (how much? how often? why?)
• Menstrual history
• Family history of eating disorders, depression, obesity, and chemical dependence

Remember: Patients will be sensitive about weight.  Check weight in a gown after voiding and facing away from the scale.  When possible, do not make comments about their weight or appearance.

Consider eating disorders for patients with:

• Amenorrhea
• Reflux/regurgitation
• Chronic constipation
• Elevated creatinine
• Metabolic disturbance
• Elevated amylase
• Bradycardia
• Syncope
• Dehydration
• Hypoglycemia

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