Type 1 Diabetes

Question 1

Epidemiology of Type 1 Diabetes

Answer 1

-Prevalence 0.5%
-Peak onset at adolescence
6/12 to 80
-M=F
-White caucasian
-Seasonal variability
-More prevalent -Northern latitudes

Question 2

Pathophysiology of T1DM

Answer 2

-Beta-cell events trigger autoimmune response
-Antibodies to insulin or GAD generally appear first
-Other beta-cell antibodies follow:
IA2, Zn2+ transporter 8
-Selective immune beta-cell destruction

Question 3

Autoimmune triggers

Answer 3

• Viral infection (Coxsackie)
• ER stress
• Cytokines

Question 4

Genetic predisposition to T1 DM

Answer 4

Associated with HLA antigen

Greater predisposition if father has it compared to mother
-As well as sibling

Twin=roughly 35%

Question 5

Pathological progression of T1 DM

Answer 5

1. Genetic predisposition (HLA regions etc)

Environmental trigger

2. Insulitis
3. Pre-diabetes
4. Diabetes

Question 6

Viral stress if T1 DM

Answer 6

Viral infection [e.g coxsackie]

Triggers autoimmune reaction that destroys beta cells

• ER stress
• Cytokines

Question 7

Symptoms

Answer 7

Lethargy '
Polyuria/Polydipsia
Blurred vision 
Infections - thrush, abscesses 
Weight loss 
Ketosis/ketoacidosis 
Death 
Age affects presentation 
-Immune attack more brisk in younger patients

Question 8

When are ketone bodies produced?

Answer 8

Metobolised when insulin is deficient and glucose cannot be used

Question 9

C-peptide

Answer 9

Measurement of insulin production
-Made in 1:1 ratio to insulin

By product of insulin metabolism

Question 10

Insulin

3 routes of administration

Answer 10

subcutaneously
inhaled
mucous membranes

Question 11

HLA antigens associated with T1DM

Answer 11

DR3-DQ2

DR4-DQ8

Question 12

2 types of ketone bodies

Answer 12

Acetone (urine)

D-beta-hydroxybutyrate (blood)

Question 13

How is glucose monitored by clinician?

Answer 13

Monitor HBA1c which is glycated haemoglobin

• Reflects glucose over last 3 months
• Weighted towards last 6 weeks
• Affected by red cell lifespan