Obesity and regulation of appetite

Question 1

What is overweight BMI?

Answer 1

25-29.9

Question 2

What BMI is associated with obesity?

Answer 2

greater than 30

Question 3

What waist circumference in men and women is associated with high risk of obesity?

Answer 3

greater than 40/35 inches

Question 4

What is the significance of waist circumference

Answer 4

indirect measure of central adiposity correlated with visceral fat. Excess fat in the abdomen is an independent predictor of risk factors and morbidity.

Question 5

What 3 factors influence intake and expenditure?

Answer 5

enviornmental and social influences, genetic makeup, individual choices

Question 6

Of the 3 components that comprise energy expenditure, what has the greatest impact?

Answer 6

basal metabolic rate (others are physical activity, thermic effect of food)

Question 7

What are afferent signals that increase appetite?

Answer 7

NE, neuropeptide Y, agouti-related peptide, ghrelin

Question 8

What are afferent signals that decrease appetite?

Answer 8

leptin, insulin, a-melanocyte-stimulating hormone)

Question 9

Afferent signals that increase appetite and those that decrease appetitie are recieved in the _____

Answer 9

hypothalamus, (lateral)

Question 10

What 5 things make up TEE? (total energy expenditure

Answer 10

1. REE: resting energy expenditure
2. TEF: thermic effect of food
3. ADL: activities of daily living
4. exercise
5. NEAT: non-exercise activity thermogenesis

Question 11

_____ integrates diverse signals like appetite and sends efferent signals to regulated energy intake and expenditure

Answer 11

Hypothalamus (lateral)

Question 12

What signals does the hypothalamus secrete that STIMULATE food intake?

Answer 12

NPY, AgRP, hypocretins, orexins

Question 13

T or F AgRP is short lived.

Answer 13

False. one injection can last several days. NPY is short lived

Question 14

How is the appetite stimulating effect of AgRP mediated?

Answer 14

Antagonism of MC3 and MC4. This reverses inhibition of food intake induced by alpha-MSH

Question 15

What hormones released by the hypothalamus to stimulate food intake may also have a role in sleep?

Answer 15

hypocretins and orexins

Question 16

What 2 receptors are part of the ECS? What do they do?

Answer 16

CB1: CNS,GI tract, adipocytes. increase appetite, motivation to eat, fat accumulation, intereferes with feelings of satiety
CB2: no role in appetite regulation

Question 17

What ANOREXIGENIC agents are released by the hypothalamus

Answer 17

CART, serotonin, melanocortins (act on MC4 receptors)

Question 18

What adipocyte-derived signals play a role in regulation of food uptake?

Answer 18

TNFa: insulin resistance
adiponectin: deficient in obese pt
Leptin: absence leads to overfeeding and massive obesity, inhibits NPY actions

Question 19

What pancreatic signals play a role in regulation of food intake

Answer 19

Insulin: deficiency/resistance associated with hyperphagia. Role in satiety and meal termination
PP: Satiety signaling and reduction of food intake

Question 20

What GI signals play a role in food intake

Answer 20

Ghrelin: stimulates GH secretion, increased food intake
PYY: satiety signal
GLP1: gut-derived satiety signal, suppress glucagon secretion
Cholecystokinin: potent satiety signal

Question 21

What are incretins?

Answer 21

GLP1 and GIP….. boost postprandial insulin secretion

Question 22

______ is the only peripheral signal activated preprandially and may be unique in its role as a rare peripheral signal for hunger and meal initiation.

Answer 22

Ghrelin

Question 23

_____ is the most common known monogenic obesity factor.

Answer 23

MC4R

Question 24

Describe the pathogenesis involved in MC4R mutations

Answer 24

a-MSH on MC4R causes decreased food intake. Mutation–> hyperphagia.
Clinical manifestations: increased linear growth, increased fat and lean body mass, increased bone mineral density, severe hyperinsulinemia

Question 25

What does leptin therapy induce?

Answer 25

weight loss

Question 26

Read over hypoglycema

Answer 26

3 pages