Complications and Comorbidities> Neurology/Psychiatry>

DEFINITION

• A group of psychiatric illnesses including anorexia nervosa, bulimia nervosa, and other eating disorders not otherwise specified (e.g. binge eating disorder, night eating syndrome) with potentially life-threatening health impact.
• Anorexia Nervosa is characterized by self-starvation and excessive weight loss, and an intense fear of weight gain.
• Bulimia Nervosa is characterized by a secretive cycle of binge eating (eating large amounts of food - more than most people would eat in one meal - in short periods of time) followed by purging (getting rid of the food and calories through vomiting, laxative abuse, or over-exercising).
• Binge Eating Disorder is characterized by feeling compelled to consume a large number of calories (i.e. 10,000 calories) over a specified time period.
• In patients with type 1 diabetes, the most common purging manifestation is deliberate insulin omission and restriction.

EPIDEMIOLOGY

• Eating disorders are very common among patients with type 1 diabetes. Insulin omission or restriction has been reported by ~ 2% among pre-teen girls, 11-15% among mid-teen years and 30%-39%  among late teenage and early adulthood (Nielsen; Jones; Colton) . The prevalence of overt eating disorder syndromes ranges from 0-11% and the prevalence of subthreshold eating disorders ranges from 7-35% (Colton). 
• Mortality rates are much higher with combined anorexia nervosa and type 1 diabetes (10-Year mortality rate= 34.6/1000 person-years) than with either condition alone (type 1 diabetes only: 10-Year mortality rate=2.2/1000 person-years; anorexia only: 10-Year mortality rate=7.3/1000 person-years) (Nielsen).
• Rates of diabetic complications (mainly retinopathy, ketoacidosis, neuropathy) are higher among people with type 1 diabetes and co-existing eating disorders. (Rydall; Peveler)
• Patients with type 2 diabetes are more likely to have binge eating disorder due to the frequent co-existence of overweight or obesity along with the need for weight control (dietary restraint) (Herpetrtz). 
• Risk factors: female sex, family history of eating disorder, history of dieting, body dissatisfaction, higher BMI, depression and anxiety disorders, personality disorder (obsessive compulsive, perfectionist, histrionic trait, impulsive), young age (although later onset is also observed).

DIAGNOSIS

• Often patients do not present with a chief complaint of a eating disorder and the eating disorders are well hidden. Deliberate insulin omission is a common behavior and patients may initially deny it.
• Formal diagnostic criteria for Anorexia Nervosa based on DSM-IV criteria include: 1) Refusal to maintain body weight at or above a minimally normal weight for height, body type, age, and activity level (~less than 85% of that expected); 2) Intense fear of weight gain or being "fat" or feeling "fat" or overweight despite dramatic weight loss; 3) Loss of menstrual periods; 4) Extreme concern with body weight and shape
• For Bulimia Nervosa the DSM-IV criteria include: 1) Recurrent episodes of binge eating in a discrete period of time involving more food than most people would eat, with a distinct feeling of lack of control during episode; 2) Recurrent inappropriate compensatory behavior to prevent weight gain, such as self-induce vomiting, misuse of laxative, diuretics, enemas or other medications, fasting or excessive exercise; 3) Both binge eating and inappropriate compensatory mechanisms occur on average at least twice a week for 3 months; 4) Extreme concern with body weight and shape.
• The DSM-IV criteria for Binge Eating Disorder (Compulsive Overeating Syndrome) includes: 1) Recurrent episodes of binge eating. Episodes defined by eating a larger amount of food than normal during a short period of time (two hours) AND feeling a lack of control over eating; 2) Three or more of: a) eating until uncomfortably full, b) eating large amounts of food when not physically hungry, c) eating more rapidly than normal, d) eating alone because embarrassed, e) feeling disgusted, depressed or guilty after overeating; 3) Marked distress that binge eating is present; 4) Binge eating occurs, on average, at least two days a week for 6 months; 5) Binge eating is not associated with inappropriate compensatory behavior (e.g., purging, excessive exercise).
• Clinical warning signs: overall deterioration in psychosocial functioning, depressive symptoms, poor body image/low self-esteem, low weight, concern expressed by family member, refractory metabolic control, amenorrhea, delay in puberty, sexual maturation or growth. Specific to diabetes: episodes of hyperglycemia and glycosuria, unexplained elevations in A1c, repeated problems with DKA.
• Extended instruments (questionnaires) are available for the formal assessment of eating disorders. Usually performed and scored by trained interviewers and not validated in diabetes (Criego).
• Clinicians working with individuals who have diabetes (especially adolescent girls and adult women) should use open-ended screening questions to understand patient's current satisfaction with body weight, patterns of insulin use and overall eating behaviours: 1) What did you eat yesterday? 2) Do you ever eat more than you want or use unprescribed laxatives, diuretics, diet pills? 3) Do you take less insulin that you should? 3) Do you think you are thin?
• Other behaviors/attitudes associated with disordered eating: excessive physical activity and restrictive eating.

SIGNS AND SYMPTOMS

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CLINICAL TREATMENT

• These diagnoses are very serious, especially with co-existing diabetes; their significance should not be ignored or minimized. 
• In patients with poorly controlled diabetes, hospitalization is recommended until medically safe. In general, patients with type 1 diabetes and eating disorders may be more difficult.
• An integrated inpatient team approach is the recommended model of care including the following: endocrinologist, psychologist/psychiatrist, general internist, specialized nutritionist, and diabetes educator. 
• Level of care needed: consider the patient's overall physical and psychological conditions, behaviors, and social circumstances rather than simply relying on one or more physical parameters such as weight.
• Basic laboratory analyses: glucose, A1c, serum electrolytes, blood urea nitrogen, serum creatinine (interpretations must incorporate assessments of weight), thyroid-stimulating hormone test; complete blood count including differential, erythrocyte sedimentation rate, liver tests, urinalysis.
• Specialized tests: electrocardiogram, osteopenia and osteoporosis assessments (amenorrhea for >6 months), serum estradiol in female patients, serum testosterone in male patients.
• Evidence-based treatment guidelines for the management of eating disorders exist for the general population (American Psychiatric Association). However the efficacy and effectiveness in patients with diabetes has not been clearly shown. Very few, small studies have been conducted in this population.

• Set small incremental goals for re-establishing patient on appropriate insulin dose, for improving overall blood glucose control and for normalizing eating patterns.
• Aim for A1c levels within safe guidelines, discourage perfectionistic goals for A1c and blood glucose (pre- and post- prandial) (Goebel-Fabbri).
• Anticipate insulin edema and fluid retention that may occur as blood glucose improves and could increase the risk of relapse.
• Consistent SMBG and insulin administration (type 1 diabetes). Medication adjustments and hypoglycemia prevention.

• Caloric intake levels should usually start at 30-40 kcal/kg per day (approximately 1,000-1,600 kcal/day). During the weight gain phase, intake may have to be advanced progressively to as high as 70-100 kcal/kg per day for some patients; many male patients require a very large number of calories to gain weight.
• Three meals with three snacks are usually needed to meet caloric goals.
• Regular monitoring of serum potassium levels is recommended in patients who are persistent vomiters. Hypokalemia should be treated with oral or intravenous potassium supplementation and rehydration. Thiamine may also be reduced in patients with vomiting.
• If severely malnourished, patients should be monitored closely for refeeding syndrome. Refeeding syndrome requires careful monitoring of electrolytes (especially for hypophosphatemia), neurologic, cardiac and pulmonary systems.
• Supplemental calcium, vitamin D and vitamin B12 are often recommended.
• Avoid focus on food labels, specially since this may be a trigger for food restriction.
• Long-term goal is to have an eating pattern consistent with insulin (or diabetes medication) administration.

• Family based interventions to promote family support in the diabetes management.
• Interventions to develop flexible approaches to food and meal planning.
• Individual or group therapies to increase self-esteem, body acceptance.
• If severe psychiatric symptoms, formal evaluation and treatments may be required.

• SSRIs are widely used in treating patients with anorexia nervosa and persistent depressive, anxiety, or obsessive compulsive symptoms and for bulimic symptoms in weight-restored patients
• Fluoxetine is the best studied of these and is the only FDA-approved medication for bulimia (recommended dose of 60 mg/day with periodic reassessment of need).

FOLLOW UP

• Monitor the patient for shifts in weight (weekly and then monthly), blood pressure, pulse, other cardiovascular parameters, glucose and other metabolic parameters.
• Monitor patients attitudes and behaviors to detect early signs of relapse.

EXPERT COMMENTS

• Eating disorders are more common among patients with type 1 or type 2 diabetes than among the general population. Patients with type 1 diabetes may be concerned about weight gain associated with intensive diabetes management. Closer attention to food, portion control and meal planning may influence attitude/behaviors negatively and favor the development of eating disorders.
• Be aware that people with eating disorders often go to great lengths to rationalize, deny or hide them. 
• Mortality and diabetic complications rates are higher among individuals with co-existing diabetes and eating disorders, compared to people with diabetes only, probably due to the increased risk of recurrent hypoglycemia and overall poor diabetic control.
• Early and routine screening is recommended. Eating disorders may go undetected until serious complications have developed. Physicians should be alert of clinical warning signs. Weight loss resulting from an eating disorder may be passed off as the result of careful diet control.
• Skipping or cutting back on insulin can mask binge eating. "Metabolic purging" refers to people failing to take insulin so that they can eat and not gain weight - a dangerous practice. 
• Many patients, particularly younger patients, have combinations of eating disorder symptoms that cannot be strictly categorized as anorexia or bulimia nervosa.
• A multidisciplinary approach constitutes the model of care.

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