Obesity

Question 1

What is the result of metabolic stress?

Answer 1

metabolic syndrome
central obesity
dyslipidemia
insulin resistance
T2DM
CVD

Question 2

How do you calculate BMI?

Answer 2

weight/height2

Question 3

What are the ranges of BMI?

Answer 3

up 25 - healthy
25-29.9 - overweight
30-39.9 - obese
>40 - morbidly obese

Question 4

What are the major factors influencing obesity?

Answer 4

genetics

environment

Question 5

What are the major contributers to disease and premature mortality?

Answer 5

T2DM
high BP
heart attack
certain cancers
osteoarthritis

Question 6

When is the risk of T2DM increased?

Answer 6

BMI of over 30

Question 7

What are the potential consequences of diabetes?

Answer 7

stroke
respiratory disease
heart diease
gall bladder disease
osteoarthritis
dementia
NAFLD
diabetes
cancer
hyperuricemia
gout

Question 8

Why do we need fat?

Answer 8

energy storage
prevention of starvation
energy buffer during illness

Question 9

What are the CNS influences on energy balance and body weight?

Answer 9

Behaviour - feeding and physical activity
ANS activity - regulates energy expenditure
Neuroendocrine system - secretion of hormones

Question 10

What is the neural centre responsible for energy intake?

Answer 10

hypothalamus

Question 11

What lesions induce leanness and obesity?

Answer 11

ventromedial hypothalamus - obesity

lateral hypothalamus - leanness

Question 12

What are the satiation signals?

Answer 12

signals that increase during a meal to limit meal size

Question 13

What are the satiation signals and where do they come from in the GI tract?

Answer 13

CCK - enteroendocrine cells -> nucleus of solitary tract in hind brain
PYY - mucosal L cells -> hypothalamus
GLP-1 - released form L cells -> Hypo and NTS
OXM - oxyntic cells of sm. intestine
Obestatine - cells lining stomach and sm.intestine

Question 14

What is the effect of PYY?

Answer 14

inhibits gastric motility, slows emptying and reduces food intake

Question 15

What is the effect of GLP-1?

Answer 15

inhibits gastric emptying and reduces food intake

Question 16

What is the effect of OXM?

Answer 16

inhibits appetite

Question 17

What is the effect of Obestatin?

Answer 17

reduces food intake

Question 18

What is the effect of Obestatin?

Answer 18

reduces food intake

Question 19

Where is ghrelin produced?

Answer 19

oxyntic cells of the stomach

Question 20

What stimulates ghrelin?

Answer 20

fasting and hypoglycaemia

Question 21

What is adaptive thermogenesis?

Answer 21

increasing energy expenditure by uncoupling oxidative metabolism from ATP production

Question 22

What is the key protein in adaptive thermogenesis?

Answer 22

UCP1

Question 23

How is UCP1 activated?

Answer 23

fatty acids

Question 24

What does UCP1 do?

Answer 24

short circuits the proton gradient in the mitochondria to accelerate fuel oxidation and produce heat

Question 25

What long-term appetite controllers stimulate food intake?

Answer 25

glutamate, gaba and opioids

Question 26

What long-term appetite controllers inhibit food intake?

Answer 26

monoamines

Question 27

What two hormones produced in peripheral tissues act on the hypothalamic neurons?

Answer 27

insulin and leptin

Question 28

Where is leptin made and release?

Answer 28

fat cells

Question 29

What do leptin and insulin communicate to the brain?

Answer 29

fat status - as fat increases do they | tell brain to eat less and burn more

Question 30

What is the Ob/Ob mouse mutation?

Answer 30

inability to produce leptin

Question 31

What is the Ob/Ob mouse mutation?

Answer 31

inability to produce leptin

Question 32

What does reduced leptin induce?

Answer 32

starvation response which causes unrestrained appetite

Question 33

What are the signs of the Ob/Ob mouse?

Answer 33

hyperphagia, reduced energy expenditure, hyperglycaemia, hyperinsulinemia

Question 34

How can you rescue the Ob mouse?

Answer 34

administering leptin

Question 35

What is different in the db/db mouse?

Answer 35

it has an leptin insensitive receptor

Question 36

What are the signs of the db/db mouse?

Answer 36

hyperglycemic, hyperinsulinemic, insulin resistant

Question 37

Where are there high levels of leptin receptor?

Answer 37

arcuate nucleus in the hypothalamus

Question 38

What are the biological roles of leptin?

Answer 38

``` food intake and energy expenditure angiogenesis tumourigenesis bone formation maintenance of reproductive system maintenance of immune system peripheral glucose homeostasis ```

Question 39

What are the roles of insulin?

Answer 39

inhibits food intake | circulates in proportion to body adiposity