Week 111 - Obesity Flashcards
What risk are women at from having a high BMI, more so than men?
Type II diabetes
What BMI is required to be considered for bariatric surgery in Wales?
50+
what type of collagen provides mechanical strength?
fibrillar - type 1
Define catabolism
breaking down complex nutrients into simple molecules
What is the main risk of having a high BMI?
CVD
What are the restrictive surgical options for morbid obesity?
laparoscopic gastric banding (LGB) laparoscopic sleeve gastectomy (LSG)
What type of collagen forms tendons primarily?
type 1
Define anabolism
building up of complex molecules required for life
What is classed as clinically obese?
30+ BMI
What are the malabsorptive surgical options for morbid obesity?
laparoscopic biliopancreatic diversion with duodenal switch (BPD with DS)
What is the function of fibril-associated collagen?
link fibrillar collagens together
What molecules is energy stored in?
ATP and NAD+
What does a BMI chart not take into account?
Age or gender
How does gastric banding and sleeve gastrectomy generally work?
decrease food intake by decreasing stomach size
What do sheet-forming and anchoring collagens function as?
Form 2D networks in basal laminae and connect it to skin/underlying connective tissue
What does NAD+ act as?
An electron carrier
Why is using a BMI chart not good for women?
Have a higher % body fat which increases with age
How does BPD with DS generally work?
decreases calorie consumption absorbed by GI tract
What do transmembrane collagens act as?
adhesive receptors
What does NAD+ become once it has been reduced?
NADH + H+
What is the best way to measure obesity?
Waist circumference
What are the combined surgical options for morbid obesity?
laparoscopic gastric bypass
What amino acids are the polypeptide chains of collagen primarily made up of?
Proline and glycine
NAD+ carries electrons associated with what process?
catabolism of O2 during respiration
What is the first line of treatment in obese patients?
Diet and physical activity
How does gastric bypass generally work?
Combines decreasing stomach size with decreasing calorie consumption
What arrangement do fibrillar collagens have?
Quarter stagger arrangement
What does NADP+ function as?
Electron donator
Why were drugs like Rimonabant removed?
Increased risk of depression and suicide
What are the problems of gastric bands?
misplacement of band band erosion half of patients will require further surgery
What is quarter stagger packing?
Molecules are displaced 1/4 of their length
NADP+ donates electrons in what processes?
Anabolic processes
What else is sibutramine used for?
antidepressant
What is done in sleeve gastrectomy surgery?
Subtotal gastrectomy (removes most of stomach) so becomes a tube
What cells compose tendons?
tenocytes and fibroblasts
Define the respiratory exchange ratio
CO2 produced / O2 used
How did Rimonabant work?
Mimiced effect of endocannabinoids in brain
What are the benefits to LSG?
reduced portion size reduced transit time - arrives faster to SI so GLP-1 released quicker
What are the function of tendons?
transmit muscle forces with minimal elongation
What fuel do red blood cells use?
glucose
What effect does GLP-1 have in humans?
decreases appetite by maintaining blood glucose levels and slows gastric emptying
What are the problems associated with LSG?
Reflux Stenosis Dilatation
What fuel do white blood cells use?
glucose
What is the mechanism of GLP-1?
decreases glucagon secretion by alpha cells in pancreas
What is done in biliopancreatic diversion with duodenal switch (BPD with DS) surgery?
Sleeve gastrectomy performed (70% stomach removed), and two pathways are created from small intestine with one common channel.
What fuel does the liver use?
fatty acids
When do levels of GLP-1 increase?
After ingestion of food
What is the aim of having two pathways in the small intestine with one common channel before entering the large intestine?
Reduce the amount of time the body has in absorbing calories from the diet in the small intestine and selectively limit the digestion of fat by forcing bile to travel down the longer pathway
What fuel does the brain use?
Glucose (or ketone bodies in starvation)
How is the digestion of fat selectively limited in a BPD with DS?
The longer pathway (biliopancreatic loop) carries bile from the liver to the common channel and the shorter pathway takes food straight to the common channel - so chance that they meet and fat is digested is lowered
State the process of B-oxidation in the liver
fatty acids –> 2 acetyl CoA + energy
What are the advantages of BPD with DS?
Can eat normal portion sizes Excellent comorbdity resolution 90% EWL at 2 yrs
Statet the process of ketogenesis in the liver
2 acetyl CoA –> 4 ketone bodies
What are the disadvantages of BPD with DS?
Very demanding operation hospital stay Lifetime high protein diet 0.5% mortality
What fuel does the heart use?
Ketone bodies
What is done in laparoscopic gastric bypass?
Bypasses most of the stomach and small intestine via food channel to avoid digestion
What fuel does the kidney cortext use?
Fatty acids and Ketone bodies
What are the problems with LRYGB?
Dumping syndrome Hospital stay
When are there high levels of ketone bodies
Starvation
What are the benefits of LRYGB?
75% EWL at 2 years Type II diabetes mellitus resolution rates 85%
How long does it take for fat to be liberated from deposits to enter the bloodstream?
15-20minutes exercise or after 24 hours starvation
What are the problems with obese patients undergoing surgery?
Intubation/ventilation problems
What happens during the first 24 hours of starvation?
Glycogenolysis Glycogen –> glucose
Give the equation for BMR
weight (kg) x 24kcal / day
What conditions increase a persons BMR?
hyperthyroidism exposure to cold regular exercise fever
What conditions decrease a persons BMR?
hypothyroidism starvation hypothermia sustained idleness
what four marcromolecules form extra cellular matrix (ECM)? cartilage
collagen elastin proteoglycans glycoproteins
Define metabolism
chemical transformations made by cells and tissues during life
How does orlistat work
prevents the digestion and absorption of fat by binding to GI lipases
What ethnicity is predisposed to a higher risk of obesity?
Pima indians
What drug used to obesity acts as a cannabinoid receptor 1 agonist?
Rimonabant
What drugs are used to decrease glucagon secretion thus hepatic glucose output, and decrease gastric emptying?
GLP-1 analogues
What is drug required to be tested before being considered for bariatric surgery?
Orlistat
What BMI is required to be considered for bariatric surgery in England?
40+ or 35+ with comorbidities
what type of cartilage is pressure tolerant?
articular cartilage
What % water is the body made up of?
55%
What is the function of protein in the body?
form structural proteins, enzymes, transport/binding proteins found in membranes/cytoplasm and blood
What is the only drug that can be prescribed to obese patients?
Orlistat
Name the obesity related comorbidity
T2DM Hypertension Obstructive sleep apnoea OA Depression Subfertility Increased rates of CV disease/cancer
What drug used to treat obesity acts as a pancreatic lipase inhibitor?
Orlistat
what do ligaments do?
link bone to bone
What firstline drug is prescribed to obese patients to treat diabetes type II?
Metformin
What drug used to treat obesity acts as a reuptake inhibitor of serotonin?
Sibutramine
What do tendons do?
link muscle to bone
What % protein is the body made up of?
19%
What % lipid is the body made up of?
19%
What is the function of water in the body?
provides medium for the rapid transport and metabolism of metabolites
How does Metformin work?
Suppresses glucose production by liver
What are the main environmental causes of obesity?
High food intake+Lack of physical activity
what type of joint is the knee?
synovial hinge
How in theory would an SNRI work as an appitite supressant?
Blocking seratonin reuptake in GUT - increased Satiety Blocking noadrenaline reuptake - increased sympathetic tone (AP firing rate) -> increased metabolism
How does Orlistat work?
Pancreatic lipase inhibitorInhibits fat absorbtion in the gut
Name some of the conditions you are at risk of by being obese?
- hypertension - stroke - type 2 diabeties - mycardial infarction (heart attack) minors: - sleep apnea - GORD - gallstones - cancer - osteoarteritis
What is the definition of Metabolic syndrome?
Someone who is- Centerally Obese (measured via waist circumfrence) - diabetic - hypertensive
What BMI is classes as obese?
> 30
