Eating Disorders

Question 1

What is anorexia nervosa?

Answer 1

Compulsive need to control eating and body shape. There is a 4:1 female to male bias but men are likely to be underdiagnosed. Typically occur in mid adolescence. Occurs as a result of a combination of biological (genetics), psychological (anxiety, depression and OCD), developmental (eating problems whilst growing up, parents with strict dieting regimes) and sociocultural (substance abuse, media exposure, image aware activities such as ballet).

Question 2

What are the two types of anorexia nervosa?

Answer 2

Two subtypes: Restrictive type and Restrictive + binge eating followed by purging

Question 3

What behaviour is seen in anorexia nervosa?

Answer 3

Overvaluation of weight loss
Belief of being fat even when very low weight
Males tend to prefer very high muscle mass over thinness
Food refusal, diet restriction, over exercising, inducing vomit and laxative abuse
Can be episodes of binge eating (subjective) followed by remorse, vomiting and concealment
Low self-worth

Question 4

What general physiological features are present in anorexia nervosa?

Answer 4

Generally: fatigue, reduced cognition, altered sleep cycles, reduced libido, sensitivity to cold, dizziness, constipation, and fullness after eating.

Question 5

What CVS features are seen in anorexia nervosa?

Answer 5

Cardiovascular: hypotension, bradycardia, prolonged QT, mitral prolapse, heart failure, cardiomyopathy, arrhythmias, and myocardial thinning.

Question 6

What skeletal changes are seen in anorexia nervosa/

Answer 6

Skeletal: Osteoporosis/osteopenia and fractures

Question 7

What metabolic features are seen in anorexia nervosa?

Answer 7

Metabolic
Low potassium, sodium, calcium, phosphate, zinc, thiamine, LH, FSH, oestrogens and testosterone and magnesium.
Raised bicarbonate, LFTs, amylase, T3/T4 (and so low TSH), raised GH, cortisol and CCK
Reduced renal function.
Glucose derangement
Amenorrhoea

Question 8

What haematological changes are seen in anorexia nervosa?

Answer 8

Haematological: bone marrow suppression, low WCC, HB and platelets

Question 9

What skin, nail and hair changes are seen in anorexia nervosa?

Answer 9

Dermatological: dry skin, brittle hair that is fine and downy

Question 10

What GI features are seen in anorexia?

Answer 10

GI: constipation, Mallory Weiss tears, pancreatitis and liver problems such as hepatitis, fatty liver disease, liver failure and risk of bleeding.

Question 11

What are the diagnostic criteria for anoreixa nervosa?

Answer 11

1. Weight <85% of predicted (allowing for height, age, sex and ethnicity) or BMI < 17.5
2. Intense fear of gaining weight or becoming fat with persistent behaviour that interferes with weight gain
3. Feeling fat when thin – body shape disturbance
4. (Amenorrhoea)?

Question 12

What red flags should you be aware of for anorexia nervosa?

Answer 12

BMI < 13 or below 2nd centile 
Weight loss > 1kg/week 
Temperature < 34.5 
BP <80/50 
Pulse < 40
O2 sats < 92% 
Limbs blue and cold 
Muscles – unable to get up without using arms for leverage 
Skin – purpura 
Blood – K<2.5, Na < 130, Phosphate < 0.5 
ECG – long QT or flat T waves

Question 13

What screening questionnaire can be used for anorexia?

Answer 13

SCOFF
Sick – do you ever make yourself sick
Control – do you worry you have lost control over eating
One stone – have you recently lost more than 1 stone over 3 months
Fat – do you believe you are fat when others say you are thin
Food – does food dominate your life

One point for every yes, >2 indicates likely anorexia nervosa diagnosis

Question 14

When helping an anorexic patient to gain weight what should you aim to achieve?

Answer 14

Aim to restore nutritional balance with weight gain of 0.5-1kg/week which is around 3500-7000 calories extra a week. Aiming for a BMI between 20-25

Explore comorbidities
Treat starvation and refer to dietician
Involve family/carers

Question 15

How do you treat severe anorexia nervosa?

Answer 15

Severe anorexia (BMI <15, rapid weight loss and evidence of system failure) 
Urgent referral to eating disorder unit, medical unit or paediatric medical wards. Refeeding is a form of treatment under the mental health act.

Question 16

How do you treat moderate anorexia nervosa?

Answer 16

Moderate anorexia (BMI 15-17.5 with no evidence of system failure) 
Routine referral to local eating disorder service or EDU if available.

Question 17

How do you treat mild anorexia nervosa?

Answer 17

Mild anorexia (BMI > 17.5) 
Build a trusting relationship, acknowledging problem and changes needed. If no response in 8 weeks consider referral to secondary care.

Question 18

What psychological management is offered in anorexia nervosa?

Answer 18

Psychological treatment – Eating disorder focused (ED) CBT, interpersonal, family, or supportive treatment.
In children and young people NICE recommends anorexia focused family therapy as 1st line followed by CBT as 2nd line.
Little evidence for medication to help, consider olanzapine which can stimulate appetite or fluoxetine but must monitor QT.

Question 19

What problems are faced when re-feeding a patient?

Answer 19

During starvation state – very low blood glucose so very low insulin. Also very low phosphate intake so intracellular phosphate used up by ATP synthesis
When refeeding occurs – rapid increase in glucose and so rapid increase in insulin, as tissues are regenerated phosphate is rapidly taken up into cells causing an abrupt decrease in phosphate (and magnesium) which is potentially fatal.

Question 20

What guidelines can help with re-feeding?

Answer 20

MARSIPAN guidelines help with managing refeeding

Question 21

What is the diagnostic criteria for Bulimia nervosa?

Answer 21

Definition

1. Recurrent episodes of binge eating characterised by uncontrolled overeating
2. Preoccupation with control of body weight
3. Regular use of mechanisms to overcome the fattening effects of binges e.g. starvation, vomiting induction laxatives or over exercise
4. BMI > 17.5

Question 22

What are the two types of bulimia nervosa?

Answer 22

Purging type – self-induced vomiting and laxative abuse

Non purging type – use exercise and fasting instead

Question 23

How common is bulimia and which sex does it effect more?

Answer 23

More common than anorexia

9:1 bias of female to male.

Associated with urbanisation and premorbid obesity. More common in female relatives of anorexics. Age of onset is usually around 18yrs.

Question 24

What are the clinical features of bulimia nervosa?

Answer 24

Fatigue, lethargy, feeling bloated, constipation, abdominal pain, oesophagitis, gastric dilatation and risk of gastric rupture, arrhythmias, cardiomyopathy (with laxative use), tetany, occasional swellings of hands and feet, irregular menstruation, erosion of dental enamel, enlarged parotids, calluses on backs of hands (Russell’s sign from induction of vomiting), oedema (use of laxatives and diuretics), metabolic alkalosis, hypochloraemia, hypokalaemia, low Na, Ca, PO and Mg.

Question 25

How is bulimia managed?

Answer 25

CBT – around 20 sessions with binge analysis
Regular eating
Guided self-help for mild cases with support
Antidepressants are helpful to reduce binges and purging (fluoxetine first line)