Eating Disorders Flashcards
What is anorexia nervosa?
https://www.youtube.com/watch?v=OMbpExKKKVo
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
- Vomiting
- Purging
- 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?
- Amenorrhoea
- Reduced libido
- Raised GH levels
- Raised cortisol
- Altered TFTs
- Abnormal insulin secretion
What are the different types of anorexia nervosa?
- Restrictive
- Binge/Purge
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
- Depression
- OCD
In terms prevalence, what is the ratio of females to males for anorexia nervosa?
10:1
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?
- Hypothermia
- Altered thyroid function
- Hypercortisolaemia
- Amenorrhoea
- Delayed puberty
- Arrested growth
- Osteoporosis
What meabolic problems occur in anorexia nervosa?
- Hypokalaemia
- Hyponatreamia
- Hypoglycaemia
- Refeeding syndrome
What renal problems can occur in anorexia nervosa?
Renal calculi
What reproductive problems can occur in someone with anorexia nervosa?
- Infertility
- Low birth weight infant
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
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 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.
