Flashcards in Obesity Deck (39):
1
What is the result of metabolic stress?
metabolic syndrome
central obesity
dyslipidemia
insulin resistance
T2DM
CVD
2
How do you calculate BMI?
weight/height2
3
What are the ranges of BMI?
up 25 - healthy
25-29.9 - overweight
30-39.9 - obese
>40 - morbidly obese
4
What are the major factors influencing obesity?
genetics
environment
5
What are the major contributers to disease and premature mortality?
T2DM
high BP
heart attack
certain cancers
osteoarthritis
6
When is the risk of T2DM increased?
BMI of over 30
7
What are the potential consequences of diabetes?
stroke
respiratory disease
heart diease
gall bladder disease
osteoarthritis
dementia
NAFLD
diabetes
cancer
hyperuricemia
gout
8
Why do we need fat?
energy storage
prevention of starvation
energy buffer during illness
9
What are the CNS influences on energy balance and body weight?
Behaviour - feeding and physical activity
ANS activity - regulates energy expenditure
Neuroendocrine system - secretion of hormones
10
What is the neural centre responsible for energy intake?
hypothalamus
11
What lesions induce leanness and obesity?
ventromedial hypothalamus - obesity
lateral hypothalamus - leanness
12
What are the satiation signals?
signals that increase during a meal to limit meal size
13
What are the satiation signals and where do they come from in the GI tract?
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
14
What is the effect of PYY?
inhibits gastric motility, slows emptying and reduces food intake
15
What is the effect of GLP-1?
inhibits gastric emptying and reduces food intake
16
What is the effect of OXM?
inhibits appetite
17
What is the effect of Obestatin?
reduces food intake
18
What is the effect of Obestatin?
reduces food intake
19
Where is ghrelin produced?
oxyntic cells of the stomach
20
What stimulates ghrelin?
fasting and hypoglycaemia
21
What is adaptive thermogenesis?
increasing energy expenditure by uncoupling oxidative metabolism from ATP production
22
What is the key protein in adaptive thermogenesis?
UCP1
23
How is UCP1 activated?
fatty acids
24
What does UCP1 do?
short circuits the proton gradient in the mitochondria to accelerate fuel oxidation and produce heat
25
What long-term appetite controllers stimulate food intake?
glutamate, gaba and opioids
26
What long-term appetite controllers inhibit food intake?
monoamines
27
What two hormones produced in peripheral tissues act on the hypothalamic neurons?
insulin and leptin
28
Where is leptin made and release?
fat cells
29
What do leptin and insulin communicate to the brain?
fat status - as fat increases do they
tell brain to eat less and burn more
30
What is the Ob/Ob mouse mutation?
inability to produce leptin
31
What is the Ob/Ob mouse mutation?
inability to produce leptin
32
What does reduced leptin induce?
starvation response which causes unrestrained appetite
33
What are the signs of the Ob/Ob mouse?
hyperphagia, reduced energy expenditure, hyperglycaemia, hyperinsulinemia
34
How can you rescue the Ob mouse?
administering leptin
35
What is different in the db/db mouse?
it has an leptin insensitive receptor
36
What are the signs of the db/db mouse?
hyperglycemic, hyperinsulinemic, insulin resistant
37
Where are there high levels of leptin receptor?
arcuate nucleus in the hypothalamus
38
What are the biological roles of leptin?
food intake and energy expenditure
angiogenesis
tumourigenesis
bone formation
maintenance of reproductive system
maintenance of immune system
peripheral glucose homeostasis
39