Anorexia Nervosa Definition Characterized by deliberate restriction of energy intake, resulting in significantly low body weight. Epidemiology • • More common in females Onset: 12 to 25. Aetiology • • • • Genetic factors - Twins ➔Higher in identical twins than in fraternal twins Neurobiological - Abnormal reward processing Psychiatric - Associated with obsessive-compulsive disorder, anxiety disorders, mood disorders, personality disorders Psychosocial factors - Traumatization - Caregiver with disordered eating - Careers or sports e.g. modelling, gymnastics, ballet. - Societal idealisation of thinness - Food insecurity Clinical Features • • • CNS - Hypothermia - Cortical atrophy with associated problems with concentration and reasoning - Seizures ➔Due to dehydration and electrolyte disturbances Cardiac - Hypotension - Bradycardia - Cardiac atrophy - Mitral valve prolapse Endocrine - Increase in stress hormones ➔ Cortisol and adrenaline - Thyroid ➔Euthyroid sick syndrome - Secondary amenorrhea • • ➔Severe weight loss -> suppression of hypothalamic-pituray gonadal axis -> hypogonadotropic hypogonadism - Impaired glucose tolerance -> hypoglycaemia MSK - Muscle weakness - Secondary osteoporosis - Stress fracture - Growth retardation in children and adolescents Skin and hair - Dry skin - Wound healing disorders - Hair loss - Lanugo body hair Types • • Anorexia nervosa, restricting type - Weight loss is achieved by any of: ➔Excessive dieting ➔Exercise ➔Fasting - No recurrent binge or purging over a 3-month period Anorexia nervosa, binge eating/purging type (ANBP) - Have restricted energy intake - AND have had recurrent binge earing and/or purging ➔Purging includes vomiting, misuse of laxatives, diuretics and/or enemas in the last three months. Diagnosis • Standard work ups: - Vitals - Bloods - CBC - Electrolytes - Creatinine - Liver enzymes - B12 - TSH - ECG Key Info Patients who have a normal or elevated BMI but meet all other criteria for AN are diagnosed with atypical AN, which is in the DSM-5 category of Other Specified Feeding and Eating Disorders. DDx • • • Bulimia nervosa - Consider for patients with ANBP Avoidant restrictive food intake disorder Body dysmorphic disorder Management • Look for red flags and if the patient required inpatient management