Eating Disorders Flashcards
What is the diagnostic criteria for anorexia nervosa?
intense fear of gaining weight or becoming fat
significantly low body weight (less than what is ideally expected) in relation to age, sex, development, and physical health
disturbance in the way one’s body weight or shape is experienced and denial of the seriousness of the current low body weight
How is the severity of anorexia classified?
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
What is the diagnostic criteria for bulimia nervosa?
recurrent episodes of binge eating
-large amounts of food consumed in short time period
-lack of control of eating during the episode
recurrent compensatory behavior to prevent weight gain
-laxatives, vomiting, diuretics, diet, drugs, exercise
binge eating and compensation 1x /week x 3 months
self-evaluation is disproportionately influenced by body shape & weight
How is the severity of bulimia classified?
based on the numbers of inappropriate compensatory behaviors per week
-mild: 1-3
-moderate: 4-7
-severe: 8-13
-extreme: 14
BN severity/diagnostic criteria does not include a specific BMI. Patients with BN are commonly normal to slightly overweight
What is the etiology of AN and BN?
genetic predisposition
-AN 22-76% heritability
-BN 30% heritability
physiologic state
-imbalance of neurotransmitters and neuropeptides
environment - complex biopsychosocial
-trauma and stress
-family dynamics
-participation in athletics with high focus on weight
-societal pressures
Describe the pathophysiology of AN and BN.
neurobiological dysfunction
-starvation, chronic stress, excessive exercise to lead to an increased release of cortisol from adrenals causing HPA, HPT, HPG suppression
neurotransmitter dysfunction
What is the impact of HPG suppression in AN and BN?
decrease in estradiol, progesterone, LH production = amenorrhea and decreased libido
What is the impact of HPT suppression in AN and BN?
TSH inhibition reduces T4 –> T3 = reduced resting metabolic state
Describe the impact of neurotransmitter dysfunction in AN and BN.
5HT is synthesized from tryptophan (from diet) and regulates postprandial satiety, mood, sleep, anxiety, impulse control, and OCD
DA deficiencies lead to decreased energy, anhedonia, decreased feelings of reward
NE deficiencies from starvation lead to hypotension, bradycardia
Compare the death rates of AN and BN.
AN: 10%
BN: 1-2%
Which psychiatric illness has the highest mortality rate?
AN
-eating disorders have high morbidity and mortality
What kind of disease is bulimia associated with an increased risk of?
CVD
What is the onset of an eating disorder usually related to?
stressful events
Describe the common course of AN.
course and outcome are highly variable
-no recovery after 1st episode
-fluctuating pattern of weight gain and loss
-chronic deteriorating course
Describe the common course of BN.
waxes and wanes
-chronic or intermittent, with periods of remission and reoccurrence
Describe the psychiatric comorbidity often seen with AN.
anxiety (OCD 30%, social phobia)
mood disorders (MDD, dysthymia, bipolar)
personality disorders
SUD
70% have other psychiatric conditions
Describe the psychiatric comorbidity often seen with BN.
personality disorders (30-50%)
substance use (30%)
anxiety (OCD, panic, social phobia)
mood disorders (MDD, dysthymia, bipolar)
impulse control disorder
Describe the general principles of treatment for eating disorders.
approaches emphasize both normalization of eating behavior and attention to underlying psychological and social issues
consider the eating abnormality to be a coping mechanism, therefore, need to develop other coping mechanisms
form a treatment alliance by offering help with sx or behaviors which are distressing to the patient
identify stressors that predispose to eating disorder
What are the risks associated with amenorrhea due to an eating disorder?
without estrogen and normal menstrual cycle increases risk of:
-osteoporosis/osteopenia
-decreased growth velocity
-lack of sexual desire/sexual dysfunction
-unexpected pregnancies
When do periods return if an eating disorder caused amenorrhea?
usually within 6 months of achieving a body weight of about 90% of the average for age and height (BMI ~19-20)
return of menstrual cycle is not related to amount of body fat but with amount of serum estrogen levels
List the electrolyte disturbances seen with AN.
dehydration
hyponatremia
hypokalemia
hypomagnesemia
hypocalcemia
hypozincemia (taste disturbances and appetite changes)
hypochloremia (if vomiting)
hypophosphatemia
hypoglycemia
List the HEENT complications seen with AN.
loss of tooth enamel
perioral dermatitis
enlarged parotid glands
List the neuro complications seen with AN.
seizures (related to large fluid shifts and electrolyte disturbances)
brain atrophy on CT
lethargy
What are examples of eating behaviors that may be seen with AN?
cutting food into small pieces
water loading
avoiding meals
vegan/vegetarian diet
calorie counting
List the cardio complications of AN.
ECG changes
bradycardia
tachycardia
orthostatic hypotension (dehydration)
dizziness and light headedness (from dehydration)
peripheral edema (cessation of laxative and diuretic abuse)
cardiac muscle atrophy
arrhythmia
What is a common ECG change seen in AN patients?
QT prolongation
-predicts cardiac arrhythmia and sudden death
-controversial (ED or electrolyte disturbances?)
requires monitoring with serial ECGs
What is the QT interval that increases the risk of torsades de pointes and cardiac death?
> 470 ms
How does cardiac muscle atrophy occur in AN?
prolonged starvation leads to wasted cardiac muscle
myofibrillar atrophy and destruction secondary to malnutrition +/- due to decreased preload
What are the consequences of cardiac muscle atrophy in AN?
decreased myocardial mass
decreased ventricular cavity size
MV prolapse
decreased contractile forces and CO
alters conduction and ventricular repolarization
What causes sinus bradycardia in AN?
due to vagal hyperactivity to decrease energy utilization
decreased T3 level may contribute
What causes cardiac arrythmias in AN?
hypokalemia due to malnutrition and diuretic abuse
What causes decreased heart rate variability in AN?
due to abnormal autonomic NS function
-predictor of sudden cardiac death
What causes hypotension in AN?
chronic volume depletion
decreased cardiac output
What is a pulmonary complication of AN?
atrophied vasculature
What are the outcomes of cardio complications in AN?
most CV abnormalities normalize with weight restoration
QTc returns to baseline
persistent MV prolapse
-little clinical significance
irreversible myocarditis with emetine toxicity
-seen with chronic ipecac ingestion