What is anorexia nervosa?
Condition most commonly seen in young women in which there is marked distortion of body image, pathological desire for thinness, and self-induced weight loss by a variety of methods
What are the diagnositc criteria for anorexia nervosa?
- Low body weight - reduced by 10-15% of expected body weight
- Self-induced weight loss - avoidance of fattening foods
- Body image distortion
- Endocrine disorders
- Delayed/arrested puberty
As part of the diagnostic criteria for anorexia nervosa, what classes as low body weight?
BMI /= 15% weight loss
How do you calculate BMI?
Weight (kg)/Height (m)2
As part of the diagnostic criteria for anorexia nervosa, what ways to individuals self-induce weight loss?
- Avoidance of fattening foods
- Excessive exericse
- Use of appetite depressants
As part of the diagnostic criteria for anorexia nervosa, what how does body image distortion normally manifest?
Dread of fatness - over valued idea, imposed low weight threshold
As part of the diagnostic criteria for anorexia nervosa, what endocrine disorders can occur in anorexia nervosa?
- Reduced libido
- Raised GH levels
- Raised cortisol
- Altered TFTs
- Abnormal insulin secretion
What are the different types of anorexia nervosa?
What is the difference between bulimia nervosa and the binging/purging subtype of anorexia nervosa?
Bulimics are often normal body weight with purging behaviour, whereas anorexic purgers are low body weight
If someone presened with symptoms of anorexia, what would be your differential diagnosis?
- Chronic debilitating physical disease
- Brain tumour
- GI disorder - Crohn's, coeliac, malabsorptive disorders
- Medications - loss of appetitie
In terms prevalence, what is the ratio of females to males for anorexia nervosa?
What is the normal BMI range?
18.5 to 24.9
What are common dental problems seen in anorexia nervosa?
Tooth decay - mainly due to vomiting
What GI problems can occur in someone with anorexia nervosa?
Constipation/Prolonged GI transit - due to:
- Delayed gastric emptying
- Gastric atrophy
- Decreased intestinal mobility
What endocrine problems occur in anorexia nervosa?
- Altered thyroid function
- Delayed puberty
- Arrested growth
What meabolic problems occur in anorexia nervosa?
- Refeeding syndrome
What renal problems can occur in anorexia nervosa?
What reproductive problems can occur in someone with anorexia nervosa?
- Low birth weight infant
What dermatological problems occur in anorexia nervosa?
- Dry scaly skin
- Hair loss
What neurological problems can occur in someone with anorexia?
- Peripheral neuropathy
- Ventricular enlargement
- Cerebral atrophy
What haematological problems can occur in anorexia nervosa?
What are specific cardiac complications that are seen in those with anorexia nervosa?
- Bradycardia (30-40bpm)
- ECG changes
- Cardiomyopathy - Decreased heart size/LV mass
- Mitral valve prolapse
What is the following, and what could it be a sign of?
Hypercarotinaemia - A yellow/orange discolouration of the skin that, unlike jaundice, does not often affect the sclerae
Occurs in anorexia nervosa, due to multiple suggested mechanisms, including:
- Diet heavy in beta-carotene foods (e.g. carrots)
- Acquired defect in metabolism of vitamin A
- Decreased catabolism of beta-lipoprotein
*Carotene is found in many fruits and vegetables. It is absorbed and eventually converted to vitamin A. Carotene absorption is enhanced by lipids (beta lipoprotein in particular), bile acids and pancreatic lipase
What is the following, and what is it suggestive of?
Russell's Sign - callused skin over the interphalangeal joints. Due to repeated self-induced vomiting over long periods of time
Indicative of either purging anorexia or bulemia nervosa
What is the following, and what is it suggestive of?
Lanugo - fine, downy hairs which grow all over the body. Most commonly found on bodies of a foetus/newborn.
Anorexia or bulimia nervosa
How would you assess someone with a suspected eating disorder?
- Full psychiatric and medical history
- Physical examination
- Sex hormones
What is this, and what could cause it?
Sialadenosis (Parotid hypertrophy) - palpable as a soft, bilateral, symmetrical and non-tender enlargement of the parotid glands. Thought to be caused by cellular hypertrophy and disturbed fat metabolism
Found in chronic alcohol misuse, but can also be found in those with malnutirition such as anorexia nervosa
What screening questionnaire can be used to screen for eating disorders?
- Sick - do you ever make youreself sick because you feel uncomfortably full?
- Control loss - Do you worry you have lost control over how much you eat?
- One stone - Have you recently lost more than one stone in a three month period?
- Fat - Do you believe yourself to be fat when others say you are too thin?
- Food domination - Would you say that food dominates your life?
When looking at FBC in someone with anorexia, what might you find?
- Normal/elevated Hb - due to dehydration
When looking at U+E's in someone with anorexia nervosa, what might you see?
- Raised urea/creatinine - dehydration
- Hyponatraemia - excessive water intake or SIADH
- Hypokalaemic, hypochloraemic metabolic aclkalosis - from vomiting
- Metabolic acidosis - laxative abuse
- Hypocalcaemia, hypomagnesaemia, hypophosphataemia
If someone with anorexia was hypokalaemic, hypomagnesaemic and hypophosphataemic, what might they be at risk of when treating their eating disorder?
When looking at bloog glucose in someone with anorexia nervosa, what might you see?
When looking at someones cholesterol leves who has anorexia nervosa, what might you see?
Dramatically elevated - due to starvation
What is refeeding syndrome?
A syndrome consisting of metabolic disturbances that occur as a result of reinstroduction of nutrition to patients who are starved, severely malnourished or metabolically stressed due to severe illness.
What is the pathogenesis of refeeding syndrome?
During starvation, insulin secretion is decreased due to decreased carbohydrate intake. Instead, fat and protein stores are catabolised to produce energy. This results in intracellular loss of electrolytes, in particular phosphate. These decreased intracellular levels may not be reflected in serum levels, which may be normal.
When food is reintroduced, insulin is secreted, resulting in increased glycogen, fat and protein synthesis. These processes require potassium, phosphate and magnesium, which is already depleted. Sudden massive cellular uptake of these electrolytes results in drops in serum levels, which results in Hypokalaemia, hypophosphataemia and hypomagnesaemia. All the clinical features of refeeding syndrome are a result of extracellular electrolyte depletion, and the failure of normal concentration gradients.
What is the most important electrolyte implicated in refeeding syndrome?
Phosphate - As phosphate (which is depleted) is required for ATP and 2,3-DPG generation, these energy molecules become depleted. The most massive consumer of phosphate during refeeding is going to be the skeletal muscle (as there is so much of it); after the hungry quadriceps has eaten all the phosphate, there will be little left for the myocardium, and this will result in the heart failure of hypophosphataemia.
What is the classic electrotlyte abnormality seen in refeeding syndrome?
How would you manage someone who is at risk from refeeding syndrome?
- Measure U+E's and correct abnormalities before feeding
- Recheck U+E's - every 3 days for first 7 days and then weekly during refeeding period
- Increase caloric intake slowly - 200-300 kcal every 3-5 days
- Monitor patient for tachycardia or oedema
- IV pabrinex/multivitamins
What is the most common cause of death in refeeding syndrome?
How would you manage someone with an eating disorder?
- Family therapy
- Fluoxetine - 60mg daily
- TCAs - for weight gain - not commonly used
When should you consider hospital admission for someone with anorexia?
- Extremely rapid weight loss
- Severe electrolyte imbalance
- Serious physiological complications
- Cardiac complications
- Marked change in mental status
- Psychosis/significant risk of suicide
- Failure of outpatient treatment
What is bulimia nervosa?
Characterised by recurrent episodes of binge eating past the point of fullness or comfort, followed by purging. There are compensatory behaviours and overvalued ideas about ideal body shape and weight. Often there is a past history of anorexia, and body weight may be normal.
How often do binges and purges have to occur for a diagnosis of bulimia nervosa to be made?
At least once per week for a period of 3 months
Besides binging and purging, how else may those with bulimia nervosa attempt to control their weight?
- Use of drugs - stimulants, diuretics
- Extreme diets
- Execrising obsessively
What are problems which occur in those that purge as part of an eating disorder?
- Cardiac failure
- Electrolyte disturbances
- Oesophageal erosions/perforation/mallory-weiss tears
- Gastric ulcers
- Dental erosions
- Hypotension - dehydration