Lec 52 Eating Disorders Flashcards
What is prevalence rate of anorexia nervosa? common in females or males?
~1% rate
more common in females [10:1 female > male]
smaller gender gap pre-puberty
What is function of mesolimbic dopamine system in feeding?
- conveys desire for food as primary rewarding substance that may or may not overlap with physiologic need
- fat, salt, and sugar strongly activate
What is function of cerebral cortex in feeding?
exerts executive control of feeding behavior –> integrates physiologic, psych, and social factors
What is anorexia nervosa?
- refusal to maintain body weight at or above normal weight for age and height
- intense fear of gaining weight despite being underweight
- distrubance in self-perception of BW/shape
What are the two subtypes of anorexia nervosa?
restricting = matintain low body weight purley by restricting food intake
binge/purge = restrict food intake AND regularly bing eat and/or purge via vomiting, laxatives, diuretics, enemas
What is difference purging with anorexia nervosa vs bulimia nervosa?
- purging in AN accompanies dietary restriction and pts are by definition underweight
- purging in BN follows binge eating and pts with BN do not necessarily have to be underweight
What is bulimia nervosa?
recurrent episodes of binge eating characterized by
- eating large amount of food in discreet time period that most would consume under similar circumstance
- sense of lack of control over eating during binge
recurrent vomiting, misuse laxative, diuretics, enemas, fasting, excessive exercising
What is prevalence rate bulimia? gender gap?
~3% of population
5:1 female > male
gender disparity narrowing
How is anorexia prevalence affected by culture? what about bulemia?
anorexia = stable prevalence reported for centuries
bulemia = varies with culture and time, more common in western culture
What is a subjective vs objective binge?
subjective = they report its a large amount of food but it actually might be a normal amount
objective = actually a large amount ~ 2 meals worth
What is course of anorexia nervosa?
phase 1: start dieting as an adolescent and it gets out of control = rapid weight loss, end up in state of starvation
- increase cortisol, dieters high
phase 2: stabilization of starvation state
- leptin decreased in response to fat loss –> suppresses HPG [hypothalamic-pituitary-gonadal] axis
- —-> decrease LH, FSH, estrogen
- adaptions to endocannabinoid system –> up regulates in order to increase dreive for food
- increased appetite vai peptide YY, Ghrelin
phase 3: weight regain
- flooding of senstized system creates dysphoria, imbalance in 5HT receptors, and in endocannabinoids
- may also have dysregulation of HPG axis
- this hormonla dysregulation contributes to relapse cycles
What are 3 early life predictors of anorexia nervosa?
- picky eating
- perfectionism
- harm avoidance
What fraction of anorexics recover?
70% relapse in 1 year
only 30% recover
What is proposed neurocircuitry of anorexia nervosa?
frontal lobe and limbic: anterior insula, ACC< oFC, parietal cortex, amygdala, striatum
- insula may be primary source of dysfunction
- AN pts over-sensitized to disgust signals –> chronic starvation may cause adaptations in insula so food presentation causes avoidance
What are morphology changes in brain with anorexia nervosa?
no diference in whitematter, large difference in grey matter correlated withd ifficulty in global processing
post-weight restoration everything seems back to normal except insula
