Diabetes mellitus

Question 1

What happens to insulin and glucose in the normal fasted state?

Answer 1

low insulin:glucose ratio

glucose concentration = 3.0-5.5mmol/L

Question 2

What processes are increased in the fasting state?

Answer 2

More lipolysis( increase in  NEFAs)
More proteolysis ( increased amino acid concentration when prolonged)

Question 3

What does the brain use for energy?

Answer 3

glucose, then ketone(needs ketogenesis)

Question 4

How is diabetes mellitus diagnosed?

Answer 4

Fasting glucose is >7.0mmol/L, random glucose >11.1mmol/L
Oral glucose tolerance test
fasting glucose
post prandial =75g glucose load, wait 2 hours
HbA1c (.48mmol/mol)
DIAGNOSIS REQUIRES 2 POSITIVE TESTS OR 1 POSITIVE AND OSMOTIC SYMPTOMS

Question 5

What is type 1 diabetes?

Answer 5

• autoimmune condition (t cell destruction of beta cells in pancreas)
• absolute insulin deficiency
• ketoacidosis occurs

Question 6

What is an example of an acute complication caused by type 1 diabetes?

Answer 6

Insulin-induced hypoglycaemia - too much insulin is administered causing reduced gluconeogenesis in liver and increased glucose uptake by the muscles.
Glucose dim circulation will continue to fall

Question 7

What are the symptoms of type 1 diabetes?

Answer 7

Weight loss
Hyperglycaemia
glycosuria with osmotic symptoms (polyuria, nocturia, polydipsia)
Ketones in blood and urine

Question 8

What are each of the osmotic symptoms?

Answer 8

polyuria - frequent need to urinate
polydipsia - excessive thirst
nocturia - waking up more than once in the night to urinate

Question 9

What are useful diagnostic tests for type 1 diabetes mellitus?

Answer 9

Antibodies: GAD, IA2 (markers)
C-peptide(low)
presence of ketones

Question 10

Pathophysiology of tpd1

Answer 10

No insulin leads to proteinolysis (AA produced)
Increased hepatic glucose output
Increased breakdowns of fat ( into non esterified fatty acids)

Question 11

How does glucose enter the cells?

Answer 11

Via glucose transporters such as GLUT-4

Question 12

Counterregulatory response to hypoglycaemia

Answer 12

Increased glucagon, catecholamins, cortisol,growth hormone

All increase hepatic glucose output w glycogenolysis ams lipolysis

Question 13

Why is hypoglycaemia bad?

Answer 13

Reduced ability to recognise symptoms of hypoglycaemia

Recurrent hypoglycaemia

Question 14

Symproms and signs of hypo

Answer 14

Autonomic: sweating
Pallor
Palpitations
Shaking

Neuroglycopenic:

Question 15

What are characteristics of GLUT -4

Answer 15

Common in myocytes and adipocytes
Highly insulin responsive
Lies in vesicles 
Recruited and enhanced by insulin 
Hphillic and Hphobic components cause a 7 fold increase in glucose uptake

Question 16

What can be used to treat a capillary blood glucose of 1.5mmol/L

Answer 16

1mg glucagon injection

Question 17

Where does insulin resistance reside ?

Answer 17

Liver, muscle and adipose tissue

Question 18

Do ketogenesis and proteolysis occur in type 2 diabetes ?

Answer 18

Have enough to supress those to begin with

Question 19

What are the consequences of insulin resistance ?

Answer 19

High triglycerides 
Low HDLS
Hypertension 
Large waist circumference
High fasting glucose (>6mmol/L)

Question 20

What is the mechanism of glucose uptake via glut4?

Answer 20

Insulin binds to insulin receptor
Insulin presence causes Glut4 vesicles to fuse with the plasma membrane
Then Glut4 allows glucose to enter cell.

Question 21

What is a glucogenic amino acid ?

Answer 21

Can be converted into glucose through gluconeogenesis

Question 22

What is a ketogenic amino acid?

Answer 22

Converted into ketone bodies

Question 23

Triglycerides can’t leave circulation, how is this over come?

Answer 23

Lipoprotein lipase (LPL) enzyme breaks them down into glycerol and non-esterified fatty acids which can then enter cells such as adipose tissue.

Question 24

What happens to glycerol in cells?

Answer 24

Converted into glucose via gluconeogenesis.
Glycerol -> dihydroxyacetone phosphate-> glyceraldhyde-3-phosphate
(For brain fuel when it’s needed)

Question 25

Does insulin promote or inhibit the conversion of proteins to amino acids?

Answer 25

Inhibits