302 Gut hormones and Obesity

Question 1

In what ways does obesity harm health?

Answer 1

-Heart disease
-Stroke
-Cancer
-Liver disease
-Reproductive complications
-Depression and anxiety
-Asthma
-Type 2 diabetes
-Osteoarthritis
-Back pain
-Sleep apnoea

Question 2

What within the body plays a role in metabolic adaptation?

Answer 2

-Decreased energy expenditure
-Thyroid hormones
-Testosterone
-Cortisol
-Gut hormones
-Leptin

Question 3

What is the function of gut hormones?

Answer 3

-Key regulators of bodyweight
-Act on homeostatic and hedonic brain circuits to modify eating behaviour

Question 4

What is the function of hedonic pathways?

Answer 4

Related to pleasant sensations
-They’re cortical brain areas that process external sensory info like reward cognition and executive functions

They interact with homeostatic signals to regulate body weight influenced by environmental conditions

Question 5

Which types of cells sense nutrients?

Answer 5

EEC

Enteroendocrine cells
-They release gut hormones as autocrine, paracrine, and endocrine regulators

Question 6

Where are EC (enterochromaffin) cells found?

Answer 6

In the stomach, small and large intestine

Question 7

Where are L cells found?

Answer 7

In the distal small intestine and colon

Question 8

Where are K cells found?

Answer 8

In the proximal small intestine

Question 9

Where are I cells found?

Answer 9

In the proximal small intestine

Question 10

Where are D cells found?

Answer 10

In the stomach (gastric corpus and antrum), and small intestine

Question 11

Where are G cells found?

Answer 11

In the stomach (antrum) and duodenum

Question 12

Where are A (X-like) cells found?

Answer 12

Mainly in the stomach

Question 13

Which gut hormones do L cells respond to?

Answer 13

GLP-1
GLP-2
PYY5-HT

Question 14

Which gut hormones do EC cells respond to?

Answer 14

5-HT

Question 15

Which gut hormones do K cells respond to?

Answer 15

GIP
5-HT

Question 16

Which gut hormones do I cells respond to?

Answer 16

CCK
5-HT

Question 17

Which gut hormones do D cells respond to?

Answer 17

Somatostatin

Question 18

Which gut hormones do G cells respond to?

Answer 18

Gastrin

Question 19

Which gut hormones do A (X-like) cells respond to?

Answer 19

Ghrelin

Question 20

Name some appetite supressing (anorexigenic) substances in the gut

Answer 20

-Peptide YY 36 (PYY)
-Glucagon-like peptide 1(GLP-1)
-Oxyntomodulin (OXM)
-Cholecystokinin (CCK)
-Glucose-dependent insulinotropic polypeptide (GIP)
-Bile acids
-Neurostatin
-Uroguanylin
-Gastric leptin
-Amylin
-FGF19

Question 21

Name some appetite inducing (orexigenic) substances in the gut

Answer 21

Ghrelin

Question 22

What is the function of the Arcuate nucleus?

Answer 22

A part of the hypothalamus that integrates circulating signals of hunger and satiety reflecting energy stores and nutrient availability

-‘Accelerator’ neurones produce NPY that stimulate feeding and blocks neuronal melanocortin receptors by producing agouti-related peptide (AgRP)
-‘Brake’ neurones produce melanocortin peptides that inhibit eating

Question 23

What is NPY?

Answer 23

Neuropeptide Y

It stimulates food intake

Question 24

Which long term regulators are released proportionate to the fat storage of the body?

Answer 24

Insulin and Leptin

They have sustained inhibitory effects of food intake while increasing energy expenditure

Question 25

What is the function of short term regulators of food intake?

Answer 25

They mark the onset and termination of eating

Question 26

What is the function of ghrelin?

Answer 26

It stimulates appetite by activating NPY/AgRP expressing neurones It rises quickly when stomach is empty and fall rapidly when food is consumed

Question 27

What is the function of Cholecystokinin?

Answer 27

It's released during eating to promote the sense of fullness that encourages an end to the meal

Question 28

What is the function of PYY (Neuropeptide Y)?

Answer 28

It decreases food intake by inhibiting gut motility It's released before nutrients arrive in the lower small intestine and the colon. Further release is stimulated by nutrients within the lower small intestine and the colon It remains high in the blood before meals and has more central effects

Question 29

What is the function of Glucagon-like peptide-1 (GLP-1)?

Answer 29

It stimulates insulin secretion and inhibits glucagon secretion

Question 30

Where is GLP-1 produced?

Answer 30

In EEC-L cells and certain neurones within the nucleus of the solitary tract in the brainstem

Question 31

What are incretins?

Answer 31

A type of gut hormones They regulate how much insulin is secreted after eating

Question 32

What is the function of DPP-4 enzymes?

Answer 32

It inactivates incretins

Question 33

What are GLP-1 receptor agonists for?

Answer 33

Medications used to treat diabetes T2 and obesity

Question 34

What effects do GLP-1 receptor agonists have on the pancreas?

Answer 34

Pancreas -Increased beta-cell function -Increased insulin biosynthesis -Increased glucose-dependent glucagon secretion -Decreased glucose-dependent glucagon secretion

Question 35

What are the effects of GLP-1 receptor agonists have on the heart?

Answer 35

-Decreased cardiovascular risk -Decreased fatty acid metabolism -Increased cardiac function -Decreased systolic blood pressure -Decreased inflammation

Question 36

What is the function of leptin?

Answer 36

It contributes to the felling of fullness It has effect son the central hypothalamus and peripheral tissues

Question 37

Where is leptin secreted?

Answer 37

Mainly in white adipose tissue It's levels are correlated with the amount of body fat

Question 38

What happens to different levels of gut hormones during a very low energy diet?

Answer 38

There is increased hunger and increased desire to eat -Significant reduction in PYY , cholecystokinin (CKK), insulin, leptin, and amylin levels -Increase in Ghrelin, GIP, and pancreatic polypeptide

Question 39

What effect does exercise have on levels of gut hormones?

Answer 39

Increased circuiting PYY Supressed appetite and ghrelin

Question 40

What is the effect of obesity on the body?

Answer 40

-Dysregulation of energy homeostatic signals -Consistent overriding of homeostatic signals of energy availability leads to disjointed eating and energy requirements -- Causes dysregulation of the metabolic mechanisms controlling energy homeostasis including secretion of gut hormones -Leptin resistance in common

Question 41

What are some psychological co-morbidities of obesity?

Answer 41

Mood disorder 15.6% Anxiety 24% Binge eating 16.3% Avoidant personality disorder 17% Substance misuse Night eating syndrome Body image disturbance Childhood maltreatment

Question 42

What is night eating syndrome?

Answer 42

When you eat a lot after dinner, have trouble sleeping, and eat when you wake up at nigh

Question 43

What is the staging tool for obesity?

Answer 43

EOSS Edmonton Obesity Staging System

Question 44

Name some medications associated with weight gain

Answer 44

Risperidone Lithium Quetiapine Aripiprazole Olanzapine Valproic acid Citalopram Duloxetine Venlafaxine Zopiclone Trazadone Zoplidem Pregablin Gabapentin Steroids Insulin

Question 45

Name some anti-obesity agents

Answer 45

CNS stimulants like Phentermin/Topiramate Phentermine Lorcaserin Benzamphetamine Bupropion/Naltrexone Orilstat Others: metoformin, zonisamide, amuylin agonists, SGLT2 inhibitors

Question 46

What effects does GLP-1 receptor agonists have on the brain?

Answer 46

Decreased body weight Decreased food intake Increased satiety

Question 47

What effects do GLP-1 receptor agonists have on the stomach?

Answer 47

Decreased gastric emptying

Question 48

What effect do GLP-1 receptor agonists have on the liver?

Answer 48

Decreased endogenous glucose production Increased hepatic insulin sensitivity Increased hepatic insulin sensitivity Decreased de novo lipogenesis Decreased steatosis

Question 49

What is steatosis?

Answer 49

Fatty liver disease

Question 50

Who qualifies for weight loss surgery?

Answer 50

Patients with BMI above 40 BMI 35-39.9 and a severe obesity related comorbidity Eg. diabetes

Question 51

What are the 4 common bariatric procedures?

Answer 51

LAGB -Laparoscopic Adjustable Gastric Banding -An adjustable band at the top of stomach Sleeve gastrectomy -Removing a large part of the stomach BPD-DS -Biliopancreatic diversion with duodenal switch -Removing a lot of the stomach and then bypassing that majority the the intestine -(Less common) Roux-en-Y -Only the top part of stomach remains and is attached directly to intestine

Question 52

What is the mechanism of weight loss after surgery?

Answer 52

-Increases in satiety promote hormones -Reduction in hunger promoting hormones -Reduced food intake -Central effects -Altered bile acid metabolism -Altered intestinal microbiota

Question 53

What is the hind gut hypothesis?

Answer 53

That diabetes control results from the expedited delivery of nutrient chyme to the distal intestine, enhancing a physiologic signal that improves glucose metabolism GLP-1 is the main contributor

Question 54

What do GIP levels correlate with?

Answer 54

The length of intestine exposed to ingested nutrients

Question 55

How does GIP stabilise glucose levels?

Answer 55

It enhances glucose-stimulates insulin secretion and promotes the secretion of glucagon when glucose is low

Question 56

What is the outcome of obesity surgery on diabetes?

Answer 56

Diabetes remission after 2 years but relapse at 10 years