Type 1 Diabetes

Question 1

What causes T1DM?

Answer 1

Beta cell destruction leading to absolute insulin deficiency

Question 2

What is required for diagnosis of T1DM?

Answer 2

Acute onset of hyperglycaemia symptoms with ketoacidosis and BSL >11.1

Question 3

Which autoantibodies are involved in T1DM?

Answer 3

Anti GAD65, anti IAA, anti IA-2 and IA-2B and anti ZnT8

Question 4

Which HLAs confer risk for T1DM?

Answer 4

HLA-DR3 and HLA-DR4

Question 5

Which HLAs confer protection for T1DM?

Answer 5

HLA-DR2

Question 6

What is the average lifetime risk of developing T1DM in the general population?

Answer 6

0.4%

Question 7

What is the risk of developing T1DM if your mother or father has it?

Answer 7

Mother: 2-4%
Father: 5-8%
Both: 30%

Question 8

What is the risk of developing T1DM if your sibling has it?

Answer 8

Non twin: 5%
Dizygotic twin: 8%
Monozygotic twin: 50%

Question 9

What is the diagnostic criteria for LADA?

Answer 9

Age of onset > 30
Positive titre for at least one autoantibody
Not treated with insulin within first 6 months after diagnosis

Question 10

What is idiopathic type 1 diabetes?

Answer 10

Accounts for 5% of T1DM

Permanent insulinopenia and ketoacidosis prone but no evidence of B cell autoimmunity

Question 11

Which other autoimmune diseases are associated with T1DM?

Answer 11

Thyroid disease, addison’s disease, coeliac disease, vitiligo, autoimmune hepatitis, myasthenia gravis and autoimmune gastritis

Question 12

Which autoimmune diseases should patients with T1DM be regularly screened for?

Answer 12

Thyroid disease, coeliac disease and autoimmune gastritis

Question 13

What is type II autoimmune polyendocrine syndrome?

Answer 13

Characterised by the presence of addison’s with autoimmune thyroid disease and/or T1DM

Question 14

What is type I autoimmune polyendocrine syndrome?

Answer 14

Candidiasis, hypoparathyroidism, addison’s disease

Question 15

Which gene is involved in type I autoimmune polyendocrine syndrome?

Answer 15

AIRE

Question 16

What is X linked polyendocrinopathy, immune dysfunction and diarrhoea?

Answer 16

A rare syndrome involving neonatal diabetes and malabsorption

Question 17

What gene is involved in X linked polyendocrinopathy, immune dysfunction and diarrhoea?

Answer 17

FOXP3

Question 18

What is the typical starting insulin regimen for T1DM?

Answer 18

0.5 units/kg/day with half as basal

Question 19

What is the benefit of using U-300 vs U-100 insulins?

Answer 19

Has a more stable, predictable and prolonged activity profile to reduce hypoglycaemia risk

Question 20

What is degludec?

Answer 20

An ultra long acting basal insulin analogue with a half life of 25 hours

Question 21

What are the benefits of CSII vs MDI?

Answer 21

Reduces HbA1c by 0.3% and reduces risk of severe hypoglycaemia

Question 22

What is the insulin carbohydrate ratio (ICR)?

Answer 22

Represents how many grams of carbohydrate are disposed of by 1 unit of insulin

Question 23

What is the insulin sensitivity factor (ISF)?

Answer 23

Represents how much 1 unit of rapid acting insulin will lower the blood glucose over 2-4 hours

Question 24

What surgical treatments are available for T1DM?

Answer 24

Whole pancreas transplantation or islet transplantation

Question 25

What is teplizumab?

Answer 25

A monoclonal antibody which targets T cells to lessen the destruction of pancreatic beta cells – shown to delay progression to T1DM in high risk patients

Question 26

What is the usual pre prandial BSL target?

Answer 26

4.4-7.2

Question 27

At what BSL would you expect to have symptoms of hypoglycaemia?

Answer 27

4

Question 28

What are the risk factors for hypoglycaemia unawareness?

Answer 28

Increasing age and diabetes duration
Aggressive glycaemic control
Frequent hypoglycaemia
Autonomic neuropathy
Beta blockade

Question 29

What are the management principles of DKA?

Answer 29

Correct hypovolaemia (initially N. Saline – change to dextrose when BSL 15)
IV insulin
Monitor and correct K+
Investigation and treatment of precipitating cause