Eating disorders Flashcards
What is the prevalence of eating disorders in males vs females?
They are 10 times more common in females
What is the incidence of anorexia in the UK?
1%
Which has a higher incidence: anorexia or bulimia?
The exact incidence of bulimia is difficult to know because many sufferers never present. However, it is estimated that the incidence of bulimia is approximately 5 times higher than that of anorexia.
Are eating disorders associated with a particular social class?
Classically, anorexia was considered to be more prevalent in higher socioeconomic classes, however, recently this seems to have changed and prevalence is pretty equal across all classes. Bulimia also has equal prevalence across all socioeconomic classes.
What are the biological factors that may provide a cause for someone developing anorexia?
Genetics play a big part - MZ twins (55%) DZ twins (5%)
Abnormalities of serotonin metabolism
What are the environmental and psychological factors that may provide a cause for developing anorexia?
Western culture - ideal body image
Relationship difficulties - both parental (overprotection, conflict avoidance, enmeshment) and peer to peer (boyfriend splitting up with patient)
Exam stress
What are the personality traits that increase someone’s chance of developing anorexia?
Inhibition
Perfectionism
Obsessionality
Harm avoidance
What are the biological factors that may provide a cause for someone developing bulimia?
Genetic component is a big part
Serotonin, noradrenaline and plasma endorphins have all been implicated (however, these could be secondary to weight loss)
Family history of depression
Early menarche
What are the environmental and psychological factors that may provide a cause for developing bulimia?
Past exposure to dieting History of childhood obesity Conflictual relationships with family Alcohol and substance misuse Personality disorders Depression
What is the cut-off BMI for anorexia in adults?
A BMI of less than 17.5 kg/m2 is characterised as anorexia.
How do you calculate a person’s BMI?
Weight (kg) / height (m) x height (m)
What are the ICD-10 criteria for anorexia nervosa?
All of the following:
- Low body weight: 15% below expected (BMI of less than 17.5 kg/m2 in adults)
- Self-induced weight loss (poor calorie intake, vomiting, exercise, etc.)
- Overvalued idea: dread of fatness, self-perception of being too fat; low target weight
- Endocrine disturbance: hypothalamic-pituitary-gonadal axis, resulting in amenorrhea, raised cortisol, growth hormone
What are the ICD-10 criteria for bulimia nervosa?
All of the following:
- Binge eating
- Strong cravings for food
- Methods to counteract weight gain (vomiting, laxatives, fasting, exercise, etc)
- Overvalued idea: dread of fatness, self-perception of being too fat; low target weight
If an anorexic patient begins to binge eat and purge, are they now classified as bulimic?
No. The key diagnostic difference is the weight and the significant generalised endocrine abnormalities. By the DSM-V they would now be classified as ‘anorexia nervosa, binge eating/purging type’.
What other psychiatric symptoms other than those specifically related to eating, might someone with an eating disorder report?
Anxiety
Depression
What are the physical complications of starvation in a patient with an eating disorder?
MUSCLES & BONES: • Emaciation (wasting of flesh) • Proximal myopathy; muscle wasting • Lanugo (fine, downy hair on trunk); loss of head hair - due to being cold • Osteoporosis; fractures REPRODUCTIVE SYSTEM: • Amenorrhea; infertility; reproductive system atrophy CARDIO: • Cardiomyopathy • Bradycardia; hypotension; cardiac arrythmias; heart failure • Peripheral oedema GI: • Constipation; abdominal pain • Cold intolerance; lethargy NEURO • Seizures; impaired concentration; depression
What are the physical complications of purging (vomiting) in a patient with an eating disorder?
- Permanent erosion of dental enamel; dental cavities
- Enlargement of salivary glands (especially parotid)
- Russell’s sign - calluses on back of hands from repeated trauma from teeth during induction of vomiting.
- Oesophageal tears; gastric rupture
What might the blood tests of an eating disorder patient show as a result of their starvation?
- Normocytic anaemia
- Leucopenia
- Abnormal LFTs
- Raised urea
- Raised cortisol
- Raised growth hormone
- Reduced T3
- Reduced FSH and LH
- Hypercholesterolaemia
- Hypoglycaemia
- Hypercarotenaemia
What might the blood tests of an eating disorder patient show as a result of their purging (vomiting)?
- Hypokalaemia
- Hypochloraemia
- Alkalosis
- Hyponatraemia
- Hypomagnesaemia
- Raised serum amylase
Other than blood tests, what investigations might you order for someone who presents with the symptoms and signs of an eating disorder?
ECG
Echo
Bone density scan
What should form the rest of your differential diagnosis for anyone that comes in with a low BMI or a history of rapid weight loss, in whom you suspect may have an eating disorder?
Malignancies
Gastrointestinal disease
Endocrine disease (eg hyperthyroidism, diabetes mellitus)
Chronic infections
Chronic inflammatory conditions
Other than eating disorders, what psychiatric disorders might lead to a patient losing weight?
Depression
Obsessive compulsive disorder
Psychotic disorders
Alcohol or substance abuse
Dementia
When should hospitalisation be considered for a patient with an eating disorder?
Body mass index of 13.5 or less
Rapid weight loss
Severe electrolyte abnormalities
Syncope
Risk of suicide
Social crisis
Can a patient be force-fed under the mental health act?
While the mental health act only makes provision for the compulsory treatment of mental illness (not physical illness), food is considered to be treatment for mental illness because it leads to improvement in psychological symptoms caused by starvation.
What is re-feeding syndrome?
A severe disturbance in electrolyte levels as a result of eating after a prolonged period of starvation. This is mostly caused by the release of insulin, which induces cellular uptake of phosphate, magnesium and potassium.
Electrolyte imbalances include: Hypophophataemia Hypokalaemia Hypomagnesaemia Hyponatraemia Metabolic acidosis Thiamine deficiency
The complications include: Muscle weakness Seizures Peripheral oedema Cardiac dysrythmias Hypotension Delirium
What are the poor prognostic factors of anorexia nervosa?
Long duration
Late age of onset
Very low weight
Associated binge-purge symptoms
Personality difficulties
Difficult family relationships
Poor social adjustment
What medication can be used in the treatment of anorexia nervosa?
Often no medication is given. SSRI’s can be used to treat co-morbid depression and obsessive-compulsive disorder.
What types of psychotherapy are most useful for patients with anorexia nervosa?
Psychoeducation about nutrition and weight
CBT
Interpersonal therapy
Family therapy - important to get family involved
Psychodynamic psychotherapy
What medication can be used in the treatment of bulimia nervosa?
High dose SSRIs can be useful to reduce bingeing and purging.
