Obesity and Metabolic Syndrome

What does satiety mean?

feeling full

How many AAs make up ghrelin?

28

What cells produce ghrelin?

neuroendocrine cells in the stomach

When is ghrelin secreted?

when the stomach is empty

What is the affect of ghrelin?

stimulates apeptite

What is an orexigenic agent?

a substance that stimulates appetite

What is an anorexigenic agent?

a substance that suppresses appetite

Give 6 examples of anorexigens produced by the gut and pancreas:

1) CCK

2) Insulin

3) GLP-1

4) Peptide YY

5) Oxyntomodulin

6) Somatostatin

True or false: nutrients like glucose and amino acids can act as anorexigens

true

What tissue produces leptin and adiponectin?

adipose

What is the function of leptin?

induces satiety by stimulating insulin secretion

What is the function of adiponectin?

induces satiety by stimulating insulin secretion

Give 2 examples of cytokines that inhibit insulin and leptin:

1) TFN-alpha

2) IL-6

Where in the brain are all central and peripheral messages surrounding appetite collected?

nucleus of the solitary tract

Where in the brain does the nucleus of the solitary tract project to?

arcuate nucleus

Where is the satiety centre located?

ventromedial nucleus

Where is the hunger centre located?

lateral hypothalamic area

Give two examples of anorexigenic neurone secretions:

1) POMC

2) CART

Give two examples of orexigenic neurone secretions:

1) AGRP

2) NPY

What molecule is used to fuel RBCs during starvation?

glucose

What two molecules are used to fuel the brain during starvation?

1) glucose

2) ketone bodies

What two molecules are used to fuel the liver during starvation?

1) glucose

2) fatty acids

What two molecules are used to fuel skeletal muscles during starvation?

1) fatty acids

2) ketone bodies

What two molecules are used to fuel adipose tissue during starvation?

1) glucose

2) fatty acids

Give 7 traits of extreme starvation:

1) diminished respiratory capacity

2) loss of heat-generating capacity

3) muscle fatigue

4) muscle wasting

5) death from respiratory/ cardiac failure or infection

6) slow heart rate

7) apathy

What BMI can be classified anorexia nervosa?

<17.5

What is a normal BMI range?

18.5-24.9

What is an underweight BMI?

<18.5

What is an overweight BMI?

25-29.9

What is an obese BMI?

over 30

Give 9 potential physiological consequences of obesity:

1) osteoarthritis

2) non-alcoholic fatty liver disease

3) hypertension

4) sleep apnoea

5) infertility

6) endometrial, breast and colon cancer

7) gall stones

8) type 2 diabetes

9) metabolic syndrome

Give the 5 traits of metabolic syndrome (of which you need 3 of for a diagnosis):

1) obesity (waist circumference)

2) type 2 diabetes

3) hypertension

4) low HDL cholesterol

5) high plasma triglycerides

What is meant my ectopic fat?

fat around viscera such as the liver, skeletal muscles and heart

How does ectopic fat alter metabolic profile?

it is less responsive to insulin and exists in a hyper-lipolytic state meaning it produces free fatty acids

What is the effect of ectopic fat producing free fatty acids?

it makes the liver less sensitive to insulin and impairs beta cell release

What causes chronic inflammation in obese people?

ectopic fat produce pro-inflammatory cytokines

Describe how cytokines from ectopic fats can lead to atheroma and CVS disease:

cytokines cause the production of reactive oxygen species which paired with dyslipidaemia, increases CVS disease and atheroma