Absorptive & Post-Absorptive State & Diabetes

Question 1

Absorptive state =

Answer 1

nutrients being absorbed into blood (fed)

Question 2

Post-absorptive state =

Answer 2

nutrients not being absorbed into blood (fasting)

Question 3

Glucose transporter responsible for glucose uptake in to pancreatic beta cells

Answer 3

GLUT-2

Question 4

Glucose transporter unregulated on body cells by insulin

Answer 4

GLUT-4

Question 5

What is happening to nutrients in the absorptive state

Answer 5

insulin is stimulating their conversion to storage products

glycogen, protein, triglycerides

Question 6

What is happening to nutrients in the post-absorptive state

Answer 6

storage products are being broken down to preserve blood glucose level

Question 7

Absorptive state:

What effect does insulin have on the liver?

Answer 7

stimulates glycogen synthesis, lipogenesis, protein synthesis

• glucose is stored as glycogen and triglycerides
• protein synthesis

inhibits glycogenolysis, lipolysis and protein catabolism

Question 8

Absorptive state:

What effect does insulin have on adipose tissue?

Answer 8

stimulates lipogenesis

• glucose is stored as triglycerides
• free fatty acids are stored as triglycerides

inhibits lipolysis

Question 9

Absorptive state: What effect does insulin have on the muscle?

Answer 9

stimulates glycogen synthesis and protein synthesis

• glucose is stored as glycogen
• amino acids are stored as protein

inhibits glycogenolysis and protein catabolism

Question 10

Why is there metabolic disturbance in diabetes

Answer 10

Lack/resistance to insulin

• high blood glucose as glucose not taken into cells by GLUT4 transporter
• compounded by no inhibition of glyogenolysis or lipolysis by insulin

Question 11

Which hormones are associated with the post-absorptive state

Answer 11

adrenaline, glucagon and growth hormone

Question 12

action of glucagon in the post-absorptive state

Answer 12

increased glycogen breakdown in liver

Question 13

action of adrenaline in the post-absorptive state

Answer 13

increased glycogen breakdown in liver, muscle, adipose tissue

Question 14

action of growth hormone in the post-absorptive state

Answer 14

decreased glucose uptake to

Question 15

Symptoms of diabetes

Answer 15

large volume of urine (polyuria) due to osmotic diuresis
thirst (polydipsia) due to dehydration
blurred vision
infections eg thrush due to impaired immune response
weight loss due to breakdown of fat and muscle
ketosis (high level of ketone bodies)
confusion
coma

Question 16

What energy sources does the body use in diabetes

Answer 16

protein and fat

triglycerides degraded to free fatty acids (lipolysis) - FFAs are put through beta oxidation in the liver to make (energy +) acetyl coA which is used in the krebs cycle or converted to ketone bodies

protein catabolism

Question 17

why do you get glycosuria in diabetes

Answer 17

renal threshold for glucose reabsorption is met

Question 18

What do ketone bodies do

Answer 18

Made in the liver, from acetyl CoA

Circulate in blood and taken into tissues, converted back to acetyl coA and used in krebs cycle

Question 19

Why is hypokalaemia a side effect of insulin treatment

Answer 19

Insulin activates Na/K ATPases on cells which causes K influx into the cell
This lowers plasma K level

Question 20

How to treat uncontrolled diabetes

Answer 20

Rehydration with IV saline - fluid loss may be massive
Insulin
Monitor electrolytes (hypokalaemia)

Question 21

Microvascular complications in diabetes include

Answer 21

retinopathy - Inappropriate angiogenesis in retina creates poor quality vessels leading to vision loss & blindness

nephropathy - damage to the kidney which can lead to chronic renal failure, eventually requiring dialysis. COMMON

neuropathy - abnormal and decreased sensation initially with feet later often fingers and hands. When combined with damaged blood vessels this can lead to diabetic foot (delayed wound healing, infection or gangrene of the foot)

Question 22

Explain how atherosclerosis is a complication of diabetes

Answer 22

Hyperlipidaemia common in diabetes. (high circulating fatty acid concentration)L. ipids are released into the circulation as VLDL and LDL – these are atherogenic

Question 23

How can diabetes cause a fatty liver?

Answer 23

Fatty acids taken up by liver and converted to triacylglycerol. This can be deposited
in the liver and lead to tissue damage – hepatic steatosis “fatty liver”

Question 24

How do ketone bodies cause ketoacidosis

Answer 24

They dissociate in the blood producing H+ which causes acidosis