T1 DM

Question 1

Epidemiology of DM

• Prevalence
• Peak onset
• Sex
• Race
• Geographical

Answer 1

Prevalence is increasing [6.7% in 16/17]
- T1 only accounts for 10-15% of all diabetes [0.5% prevalence]

Peak onset at adolescence
- Can present from 6 months to 80 [basically any age]

Affects males and females equally
- Slightly more male in UK

White caucasian
- More prevalence in the northern poles

Question 2

Genetic predisposition to T1 DM

Answer 2

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

Twin= roughly 35%

HLA regions
- DR3-DQ2
- DR4- DQ8
Can be used to identify individuals at high risk and put interventions in place.
Also used to differentiate T1 and T2 DM [as measures of diagnosing is not very accurate currently]

Question 3

Pathophysiology of T1 DM

- Not completely understood

Answer 3

Autoimmune

• Viral infection causes autoimmune attack
• Selective beta-cell damage

Antibodies against

• Insulin
• GAD [glutamate decarboxylase]

Other antibodies against

• Ia2
• Zn2+ transporter 8

More antibodies= increased change of developing T1 DM

Question 4

Pathological progression of T1 DM

Answer 4

1. Genetic predisposition
   - HLA regions etc

Environmental trigger

2. Insulitis
3. Pre-diabetes
4. Diabetes

Question 5

Viral stress of T1 DM

Answer 5

Viral infection [e.g coxsackie]

Triggers autoimmune reaction that destroys beta cells

• ER stress
• Cytokines

Question 6

Associations with T1 DM

Answer 6

Coeliac

Hypothyroidism

Graves’

Addison’s

Hypogonadism

Pernicious

Vertiligo

Question 7

Symptoms

Answer 7

Lethargy

Polyuria/ polydipsia

Blurred vision [swelling of lens]

Infections

• Thrush
• Abscesses

Weight loss

Ketosis/ ketoacidosis

Death

Age affects presentation
- Immune attack more brisk in younger patients

Question 8

Ketone bodies

Answer 8

Acetone
Acetoacetate
D-beta-hydroxybutyrate

Metabolised 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 treatment

Answer 10

Administered subcutaneously

• Can also be inhaled in US [fear of increased risk of cancer]
• Mucous membrane

Question 11

Insulin pen

Answer 11

Mode of insulin administration
- Contains needle injected subcutaneous

Sites of injection

• Lower abdomen
• Bum
• Upper outer thighs
• Upper outer arms

Question 12

Physiological insulin secretion

Answer 12

Increases just after each meal

Question 13

Basal bolus insulin

Answer 13

Basal insulin
- Long acting background insulin

Then rapid acting insulin given just before a meal
- Bolus

Question 14

Carbohydrate count

Answer 14

Allows insulin calculation according to how much carbohydrate is being consumed

Question 15

Factors that affect the absorption of insulin

Answer 15

Factors that affect blood glucose

• Diet
• Injection site
• Temperature
• Exercise
• Illness
• Stress
• Alcohol
• Menstrual cycle

Question 16

Subcutaneous insulin pump

Answer 16

Administers constant insulin supply throughout the day

• Gives basal insulin
• Allows flexibility
• Can still give bolus pumps

Pump only needs to be changed 2/3 days.

Question 17

Transplantations

• Pancreas
• Islet

Answer 17

Pancreas

• Not commonly done
• Surgery is very invasive [3% mortality], immunosuppressants increase other diseases
• Also not enough pancreases available.
• Only given when already on immunosuppressant and having surgery [SPK, PAK]

Islet cell

• Fusing healthy islet cells into the liver
• Still requires immunosuppressants
• Does not always cure.

Question 18

Glucose monitor

Answer 18

Prick finger
- Place blood on tester at least 4x daily

Glucose sensor [CGMS]
- Gives a constant trace throughout the day

Can also monitor ketone.

Question 19

Freestyle libre CGMS

Answer 19

Does not require pricking finger

Gives constant glucose reading when directed

Question 20

Monitoring HbA1c

Answer 20

Measuring glycated haemoglobin

But affected by shorter red cell life span.