16. Eating Disorders

Question 1

Define: Eating Disorders (1)

Answer 1

• eating disorders are characterized by a persistent disturbance of eating that impairs psychosocial functioning or health

Question 2

Name: Eating Disorders (6)

Answer 2

• anorexia nervosa
• avoidant/restrictive food intake disorder
• binge eating disorder
• bulimia nervosa
• pica
• rumination disorder

Question 4

Describe epidemiology: Eating Disorders (3)

Answer 4

• anorexia nervosa (AN): 1% of adolescent and young adult females; onset 13-20 yr old
• bulimia nervosa (BN): 2-4% of adolescent and young adult females; onset 16-18 yr old
• F:M=10:1; mortality 5-10%

Question 5

Describe etiology: Eating Disorders (6)

Answer 5

• multifactorial: psychological, sociological, and biological associations
• individual: perfectionism, lack of control in other life areas, history of sexual abuse
• personality: obsessive-compulsive, histrionic, borderline
• familial: maintenance of weight equilibrium and control in dysfunctional family
• cultural factors: prevalent in industrialized societies, idealization of thinness in the media
• genetic factors
  
  • AN: 6% prevalence in siblings, with one study of twin pairs finding concordance in 9 of 12 monozygotic pairs versus concordance in 1 of 14 dizygotic pairs
  • BN: higher familial incidence of affective disorders than the general population

Question 6

Name risk factors: Eating Disorders (9)

Answer 6

• physical factors:
  
  • obesity
  • chronic medical illness (i.e. DM)
• psychological factors:
  
  • individuals who by career choice are expected to be thin
  • family history (mood disorders, eating disorders, substance abuse)
  • history of sexual abuse (especially for BN)
  • homosexual males
  • competitive athletes
  • concurrent associated mental illness (depression, OCD, anxiety disorder [especially panic and agoraphobia]
  • substance abuse [specifically for BN])

Question 7

Describe: Eating Disorder Screening

Answer 7

Eating Disorder Screening

Method to identify patients with eating disorders. A “Yes” to two or more questions is associated with a sensitivity and specificity of 78 and 88 percent, respectively

SCOFF

• Do you make yourself Sick because you feel uncomfortably full?
• Do you worry you have lost Control over how much you eat?
• Have you recently lost more than One stone (14 pounds or 6.35 kg) in a 3 mo period?
• Do you believe yourself to be Fat when others say you are too thin?
• Would you say that Food dominates your life?

Question 8

Name DSM-5 diagnostic criteria: Anorexia Nervosa (4)

Answer 8

1. intake and weight: restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health; significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected
2. fear or behaviour: intense fear of gaining weight or of becoming fat, or persistent behaviour that interferes with weight gain, even though at a significantly low weight
3. perception: disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight

• specifiers: partial remission, full remission, severity based on BMI (mild = BMI >17 kg/m2, moderate = BMI 16-16.99 kg/m2, severe = BMI 15-15.99 kg/m2, extreme = BMI <15 kg/m2), type (restricting = during last 3 mo no episodes of binge-eating or purging vs. binge-eating/purging type = in last 3 mo have participated in recurrent episodes of binge-eating/purging)

Question 9

Describe management: Anorexia Nervosa (8)

Answer 9

• psychotherapy: individual, group, family: address food and body perception, coping mechanisms, health effects
• medications of little value
• outpatient and inpatient programs are available
• inpatient hospitalization for treatment of eating disorders is rarely on an acute basis (unless there is a concurrent psychiatric reason for emergent admission i.e. suicide risk)
• criteria to admit to medical ward for hospitalization: <65% of standard body weight (<85% of standard body weight for adolescents), hypovolemia requiring intravenous fluid, heart rate <40 bpm, abnormal serum chemistry, or if actively suicidal
• agree on target body weight on admission and reassure this weight will not be surpassed
• monitor for complications of AN
• monitor for refeeding syndrome

Question 10

Describe: Refeeding syndrome (3)

Answer 10

• potentially life-threatening metabolic response to refeeding in severely malnourished patients resulting in severe shifts in fluid and electrolyte levels
• complications include
  
  • hypophosphatemia
  • congestive heart failure
  • cardiac arrhythmias
  • delirium
  • death
• prevention:
  
  • slow refeeding
  • gradual increase in nutrition
  • supplemental phosphorus
  • close monitoring of electrolytes and cardiac status

Question 11

Name: Athletic Triad (3)

Answer 11

• Disordered eating
• Amenorrhea
• Osteoporosis

Question 12

Some patients with insulin-dependent DM may do what in order to lose weight? (1)

Answer 12

stop their insulin

Question 13

Describe prognosis: Anorexia Nervosa (5)

Answer 13

• early intervention much more effective (adolescent onset has much better prognosis than adult onset)
• 1 in 10 adolescents continue to have AN as adults
• with treatment, 70% resume a weight of at least 85% of expected levels and about 50% resume normal menstrual function
• eating peculiarities and associated psychiatric symptoms are common and persistent
• long-term mortality: 10-20% of patients hospitalized will die in next 10-30 yr (secondary to severe and chronic starvation, metabolic or cardiac catastrophes, with a significant proportion committing suicide)

Question 14

Name DSM-5 diagnostic criteria: Bulimia Nervosa (6)

Answer 14

1. recurrent episodes of binge-eating; an episode of binge-eating is characterized by both of the following
   
   • eating, in a discrete period of time, an amount of food that is definitely larger than what most individuals would eat during a similar period of time and under similar circumstances
   • a sense of lack of control over eating during the episode
2. recurrent inappropriate compensatory behaviour in order to prevent weight gain, such as self-induced vomiting, misuse of laxatives, diuretics, enemas, or other medications, fasting, or excessive exercise
3. the binge-eating and inappropriate compensatory behaviours both occur, on average, at least once a week for 3 mo
4. self-evaluation is unduly influenced by body shape and weight
5. the disturbance does not occur exclusively during episodes of AN

• specifiers: partial remission, full remission, severity (measured in # of inappropriate compensatory behaviours/wk: mild = 1-3, moderate = 4-7, severe = 8-13, extreme = 14+)

Question 15

Name associated features: Bulimia Nervosa (6)

Answer 15

• fatigue and muscle weakness due to repetitive vomiting and fluid/electrolyte imbalance
• tooth decay
• swollen appearance around angle of jaw and puffiness of eye sockets due to fluid retention
• reddened knuckles, Russell’s sign (knuckle callus from self-induced vomiting)
• trouble concentrating
• weight fluctuation over time

Question 16

Describe management: Bulimia Nervosa (4)

Answer 16

• admission for significant electrolyte abnormalities
• biological:
  
  • treatment of starvation effects
  • SSRIs (fluoxetine most evidence) as adjunct
• psychological:
  
  • develop trusting relationship with therapist to explore personal etiology and triggers
  • CBT
  • family therapy
  • recognition of health risks
• social:
  
  • challenge destructive societal views of women
  • use of hospital environment to provide external patterning for normative eating behaviour

Question 17

Describe prognosis: Bulimia Nervosa (4)

Answer 17

• relapsing/remitting disease
• good prognostic factors: onset before age 15, achieving a healthy weight within 2 yr of treatment
• poor prognostic factors: later age of onset, previous hospitalizations, individual and familial disturbance
• 60% good treatment outcome, 30% intermediate outcome, 10% poor outcome

Question 18

Define: Binge-Eating Disorder (4)

Answer 18

• recurrent episodes of binge-eating (as defined by criteria A of BN) that are associated with
  
  • eating much more rapidly than normal
  • eating until feeling uncomfortably full
  • eating large amounts when not physically hungry
  • eating alone because embarrassed by how much one is eating
  • feeling disgusted with self/depressed, very guilty afterwards at least once/wk x 3 mo
• not associated with any compensatory behaviours
• dieting usually follows binge-eating (vs. BN where dysfunctional dieting typically precedes binge- eating)
• associated with health consequences (i.e. increased risk of weight gain, obesity)

Question 19

Describe etiology: Binge-Eating Disorder (2)

Answer 19

• F:M = 2:1
• begins in adolescence or young-adulthood

Question 20

Describe tx: Binge-Eating Disorder (1)

Answer 20

• Cognitive behavioral therapy (CBT)

Question 21

Define: Avoidant/Restrictive Food Intake Disorder (2)

Answer 21

• eating/feeding disturbance to the extent of persistent failure to meet appropriate nutritional and/or energy needs, resulting in significant weight loss/growth failure and nutritional deficiencies;
• patients experience disturbances in psychosocial functioning and may become dependent on enteral feeding/ oral nutritional supplementation
  
  • does not occur during an episode of AN or BN
  • no evidence of distress in the way in which one’s body weight or shape is experienced

Question 22

Name risk factors: Avoidant/Restrictive Food Intake Disorder (2)

Answer 22

• temperament (i.e. anxiety disorders), environment (i.e. familial anxiety), genetic (i.e. history of GI conditions)
• begins in infancy and can persist into adulthood

Question 23

Describe tx: Avoidant/Restrictive Food Intake Disorder (3)

Answer 23

• psychoeducation
• behaviour modification
• psychotherapy

Question 24

Name Physiologic Complications: Starvation/Restriction (10)

Answer 24

• General: Low BP, low HR, significant orthostatic changes ± syncopal episodes, low temperature, vitamin deficiencies
• Endocrine: Primary or secondary amenorrhea, decreased T₃/T₄
• Neurologic: Seizure (decreased Ca2+, Mg2+, PO₄3-)
• Cutaneous: Dry skin, lanugo hair, hair loss or thinning, brittle nails, yellow skin from high carotene
• GI: Constipation, GERD, delayed gastric emptying
• CVS: Arrhythmias, CHF
• MSK: Osteoporosis secondary to hypogonadism
• Renal: Pre-renal failure (hypovolemia), renal calculi
• Extremities: Pedal edema (decreased albumin)
• Lab values:
  
  • Starvation: decreased RBCs, decreased WBCs,decreased LH, decreased FSH, decreased estrogen, decreased testosterone, increased growth hormone, increased cholesterol.
  • Dehydration: increased BUN

Question 25

Name Physiologic Complications: Binge-Purge (7)

Answer 25

• General:
  
  • Russell’s sign (knuckle callus)
  • Parotid gland enlargement
  • Perioral skin irritation
  • Periocular and palatal petechiae
  • Loss of dental enamel and caries
  • Aspiration pneumonia
  • Metabolic alkalosis secondary to hypokalemia and loss of acid
• GI: Acute gastric dilation/rupture, pancreatitis, GERD, hematemesis secondary to Mallory-Weiss tear
• CVS: Arrhythmias, cardiomyopathy (from use of ipecac), sudden cardiac death (decreased K+)
• MSK: Muscle wasting
• Renal: Renal failure (electrolyte disturbances)
• Extremities: Pedal edema (decreased albumin)
• Lab values:
  
  • Vomiting: decreased Na+, decreased K+, decreased Cl-, decreased H+, increased amylase; hypokalemia with metabolic alkalosis
  • Laxatives: decreased Na+, decreased K+, decreased Cl-, increased H+; metabolic acidosis