111 - Obesity Flashcards
What BMI is obese? What is morbid obesity?
obese = 30 Morbid = 40+
What is the only currently licenced drug for obesity?
Orlistat - intestinal lipase inhibitor - can’t absorb TG so you poo it instead.
What was wrong with the drug rimonabant in obesity?
Increased suicide risk - a cannabis receptor blocker
What new drug class are being trialed in obesity?
GLP-1
Involved in diabetes, causes weight loss and reduces appetite.
What are 2 restrictive bariatric surgeries?
Gastric banding Sleeve gastrectomy (gold standard)
What is an example of a malabsorptive bariatric surgery?
BPD with DS - bilio-pancreatic diversion with duodenal switch
- can cause malnutrition
- 90% weight loss
What is an example of a combined bariatric surgery?
Gastic bypass LGB
- V common in USA.
Where is the ‘set point’ of weight regulated?
hypothalmus
Describe the blood glucose feeding circuit
Eat -> increase blood glucose -> Ventromedial hypothalmus turned on -> fullness felt -> stop eating
Stop eating -> low blood glucose -> lateral hypothalmus on -> hunger felt -> eat
How is Ghrelin involved in appetite regulation?
Signals hunger
Produced in stomach
Calorie intake stimulates it
How is insulin involved in appetite regulation?
It is an adiposity signal
Increase blood glucose - > insulin released, decreased feeding, stimulates the hypothalamus to release anorexigenic peptides
How is mood linked to appetitie?
Serotonin is realised in anticipation of a meal - antidepressants that act on serotonin -> feel fullness
How is the endocannabinoid system involved in appetite control?
Hedonic + homeostatic role
The active ingredient in cannabis, Delta 9THC stimulates appetite.
A deficiency in what causes server early onset obesity?
Leptin deficiency - give leptin, treats them.
Describe how leptin is involved in appetite regulation
Increased leptin in blood -> acruate nucleus detects -> anorexogenic peptides are released eg. alpha MSH and CART -> inhibits feeding
Decreased leptin in blood -> arcuate nucleus detects -> Orexigenic peptides released -> NPY and AgRP released -> actives feeding
What receptor is activated by alpha MSH and blocked by AgRP?
Melacortin receptor
- involved in 1% of inherited obestiy
Which gives more energy when broken down, glucose or fat?
Fat - 50ATP per 100g
glucose only 20ATP per 100g
What are the major fuels for cellular respiration?
Glucose, fatty acides, ketone bodies, amino acids, lactate
What are minor fuels for cellular respiration?
Fructose, Galactose, Glycerol, Alcohol
Where is energy stored in the body?
Individual cells
Liver - glycogen
Depots - fat and protein
When you lose weight which stores get used first?
Carbs used rapidly
Tissue protein lost initially
Fat then becomes prodominant fuel
After how long fasting is fat used?
24hrs
What becomes the gut in embryology?
The yolk sac gets pinched off and surrounded by endoderm
When does the oesophagus first form?
Week 7/8
