Eating Disorders Flashcards
Definition and presentation of anorexia nervosa. What is the common age of onset
An intense fear of gaining weight leading to a persistent pattern of reduced energy intake (restricted eating), purging behaviours (self-induced vomiting, laxative or enema use) and/or increased energy expenditure. This leads to extreme emancipation.
- Low body weight: 15% below expected body weight/ less than 5th percentile BMI-for-age in children and adolescence (BMI <18.5)
- Often accompanied with distorted body image and a ‘dread’ of gaining weight
- Associated with endocrine dysfunction: amenorrhoea, reduced sexual interest/impotence, eleveated GH levels, deranged TFTs, abnormal insulin secretion
- Age of onset generally 16-17
How can AN be classified
- Divided into AN with ‘significantly low’ body weight (BMI> 14kg/m2) and AN with ‘dangerously low’ body weight (BMI<14Kg/m2)
Definition and presentation of Bulimia Nervosa, how can it be distinguished from AN
Frequent, recurrent episodes of binge eating (once per week or more for at least 1 month) followed by repeated, inappropriate purging (compensatory.) A binge eating episode is a confined period where the patient feels unable to control or stop eating (get urgency and compulsion). People with BN often feel fat and are preoccupied with an ideal ‘body image.’
- BMI> 18.5kg/m2, unlike AN, people with BN have normal or slightly increased body weight
- Patients maintain normal endocrine function
- May have a previous history of Anorexia
Definition of ‘binge eating disorder’
The pattern of binge eating seen in BN, often accompanied by feelings of guilt or disgust, but without compensatory purging. This can lead to obesity
Definition of avoidant/ restrictive food intake disorder (ARFID)
Insufficient quantity or variety of food intake to meet their energy or nutritional requirements, in the absence of bodyweight or shape concerns.
Who is at risk of eating disorders
What is the mortality associated with EDs
- Girls and young women aged 12-20 are at most risk of developing an eating disorder, though the incidence is currently rising in men (15-20% of cases- fewer present)
- Anorexia nervosa has also been observed in women over the age of 70
- Mortality rates associated with eating disorders are higher than any other mental illness, including depression and schizophrenia
- Premature death is a result of physical decline, as well as suicide (2/3 physical health complication leading to total organ failure, 1/3 suicide)
What is the prevalence of each ED subtype
- Other Specified Feeding or Eating Disorder (OSFED/EDNOS) (5%)
- Binge Eating Disorder (3-4%)
- Bulimia Nervosa (1-2%) likely underdiagnosed
- Anorexia Nervosa (0.5%)- 1:10 male:female incidence
- Avoidant-restrictive food intake disorder (~5% of children)
What factors confer a risk of ED
- Genetics: Female siblings of patients with an ED have a 6-10% lifetime risk.
- Neurobiological factors: Neuroimaging can be inconsistent and confounded by starvation, however there may be abnormal connectivity between the striatum and prefrontal cortex (reward and control)
- Psychological factors: Associated with obstetric complications, lack of adaptive coping strategies, personality traits (easily anxious or shy, perfectionism, rigidity, impulsivity), low self-esteem, depression and anxiety
- Sociocultural: There is societal pressure to be thin
- Psychiatric comorbidity: Up to 75% express comorbid psychiatric illness (anxiety, depression, OCD, BDD, substance misuse so there is significant overlap
- Depression: Complicated because low mood, anergia, anhedonia and poor concentration are symptoms of starvation. Depressive symptoms prior to weight loss and persistence after weight loss constitute true pathology
- Anxiety: There is a high lifetime prevalence of anxiety disorders which often predate EDs. These include social phobia and OCD. These obsessional and compulsive routines are associated with starvation but are exclusive to food, eating, weight, shape and exercise (not cleaning etc)
What factors can perpetuate EDs
Maintaining factors: starvation causes difficulty concentrating, black and white thinking, losing sight of the bigger picture, low mood, bloating and body fluctuations which can be associated with losing control over body. Unhelpful reactions from family can also perpetuate anxiety.
Differentials for EDs
Unintentional weight loss requires a thorough history and MSE. People without EDs usually have a realistic understanding of their wight and want to regain lost weight. Suspect Eds or the following when somebody denies deliberate weight loss:
- Organic causes: malignancy, chronic infection, GI pathology (coeliac, crohns, oesophageal stricture), endocrine dysfunction
- Affective disorders: Weight loss can be severe in depression and mania
- Anxiety disorders: OCD can cause food avoidance. In body dysmorphic disorder (BDD), people believe that part of their body is abnormal or ugly i.e could be fat
- Psychosis: can cause food restrictions from persecutory delusions (food is poisoned) or grandiose delusions (no need to eat)
- Autism spectrum disorder: associated with ridged eating habits and preferred foods
- Differentials for BED> depression, organic and genetic conditions (Kluver-Bucy, Prader-Willi)
What are the physical complications of EDs
Improtant ones: Prescence of lanugo hair, swollen parotids and submandibular gland, thickening of scalp, feeling cold, oedema, neuropathies and loss of libido.
What is the SCOFF questionnaire
- A useful screening tool- go to further history if positive (2 or more, or strong suspicion of ED):
- Do you make yourself feel sick because you are uncomfortable when full?
- Do you worry you have lost control over how much you eat?
- Have you recently lost one stone in a 3 month period?
- Do you believe yourself to be fat when others say you are thin?
- Would you say food dominates your life?
Aside from the SCOFF questionnaire, what other factors are important to question in a history
- Determine what led to assessment and their motivation to change
- Assess for symptoms of ED: Current weight and BMI, duration of symptoms, weight control behaviours including binging and abnormal eating, amount of exercise, vomiting and use of laxatives, beliefs about body image, desired weight and menstrual history.
- Additionally should do physical observations including BG, lying/ standing BP (look for postural BP drop), sit up-squat-stand (SUSS) test (can be impaired in AN due to proximal myopathy)
- Should then establish the biopsychosocial consequences of the ED
- Biological symptoms: feeling cold and tired, proximal myopathy, dry skin, thickening of scalp, increased body hair, oedema, dizziness, sexual dysfunction
- Psychological symptoms: low self-esteem, shame and guilt, anxiety and irritability
- Social symptoms include: isolation, social withdrawal
Easy to forget psychological and social symptoms
Blood tests in ED
- FBC- Hb can be raised in dehydration, U&Es, LFTs including albumin
- amylase (indicates vomiting)
- Cortisol and ESR- look for an organic cause
When should a patient be admitted for an ED (to an EDU)
People with mild or low-risk presentations may be managed in the community however, early referral to an EDU is advised for complex or high-risk presentations (treatment within 3 years is associated with a 90% recovery rate). Inpatient treatment may be necessary if:
- BMI < 13 or extremely rapid weight loss
- There are serious physical complications
- High suicide risk
