Lecture 3: T1DM

Question 1

What are the three tests used to diagnosis diabetes mellitus?

Answer 1

1. Fasting blood glucose
2. 75g oral glucose tolerance test
3. HbA1c

Question 2

What is the criteria to diagnosis diabetes mellitus?

Answer 2

Needs 2 abnormal tests or 1+ symptoms

Question 3

What are the levels of blood glucose in the fasting blood glucose test that indicate diabetes?

Answer 3

< 6.0mmol/l: normal

6.1-6.9mmol/l: impaired

> 7mmol/l: diabetes

Question 4

What are the levels of blood glucose in the oral glucose tolerance test that indicate diabetes?

Answer 4

< 7.7mmol/l: normal

7.8-11mmol/l: impaired

> 11.1mmol/l : diabetes

Question 5

Which diagnostic test is the gold standard for diagnosing diabetes mellitus?

Answer 5

HbA1c

Question 6

Name the different types of diabetes?

Answer 6

• Categories in relation to their cause
• Type 1 (prevalence 0.5%)
• Type 2 (prevalence 5%)
• Maturity-Onset Diabetes of the Young (MODY)
• Gestational
• Secondary

Question 7

Define secondary diabetes?

Answer 7

Defined as a diabetic condition that develops after the destruction of the beta-cells in the pancreatic islets and/or the induction of insulin resistance by an acquired disease

e.g. pancreatitis, cystic fibrosis

Question 8

What classes of diabetes can be described as insulin deficient

Answer 8

Those that are characterised by lacking insulin

• Type 1 diabetes
• MODY
• Pancreatitis
• Cystic fibrosis

Question 9

What classes of diabetes can be described as insulin resistant

Answer 9

Those that are characterised by the inability of the body to react to insulin

• Type 2 diabetes
• Gestational
• Steroid-induced

Question 10

Which auto-antibodies are associated with Type 1 diabetes

Answer 10

• Islet cell antibody (ICA)
• I-A2
• Insulin auto-antibody (IAA)
• GAD65
• ZnT8

Question 11

Which susceptible genes are associated with type 1 diabetes

Answer 11

• HLA eg DR3/4 – DR2/8
• Insulin (VNTR)
• PTPN22
• IL2RA
• CTLA-4
• IFIH1

Question 12

HLA system is a gene complex encoding the___ proteins

Answer 12

The major histocompatability complex (MHC)

Question 13

Diabetes mellitus is associated with what other conditions?

Answer 13

Other autoimmune diseases eg

• Thyroid disease
• Coeliac disease
• Addison’s disease
• Inflammatory bowel disease (IBD)
• Premature ovarian failure

Question 14

Into which layer is insulin injected into

Answer 14

The subcutaneous layer

Question 15

Which gene is the most common of mongeneic diabetes

Answer 15

HNF-1 alpha (60%)

Question 16

Explain the aetiology of monogenic forms of diabetes

Answer 16

• MODY is caused by a mutation (or change) in a single gene.
• If a parent has this gene mutation, any child they have, has a 50% chance of inheriting it from them. If a child does inherit the mutation they will generally go on to develop MODY before they’re 25
• The most common types of MODY are, based on effected gene:
  
  • HNF-1 alpha (60% of cases are due to this gene)
  • Mutation in the gene the encodes for glucokinase (20%)
  • HNF-4 alpha (5%)
  • HNF-1 beta (2%)

Question 17

Describe neonatal diabetes?

Answer 17

• it’s not an autoimmune condition
• its caused by a change in a gene which affects insulin production
• Diagnosed with diabetes under the age of 6 months
• most common cause are mutations in:
  
  • ABCC8
  • KCNJ11

Question 18

Which diabetes is diagnosed under 6 months?

Answer 18

Neonatal diabetes

Type 1 diabetes doesn’t affect anyone under 6 months.

Question 19

What are the two main forms of monogenic diabetes?

Answer 19

Some rare forms of diabetes result from mutations or changes in a single gene

1. Neonatal Diabetes Mellitus
2. MODY

Question 20

Neonatal diabetes tested for in all patients diagnosed with diabetes under what age?

Answer 20

9 months old

Question 21

What does a diabetic pump do

Answer 21

• Uses rapid acting insulin
• It can deliver basal infusion and multiple bolus doses throughout the day.
• Allows correction doses to be given preventing stacking.
• Requires regular testing, carbohydrate counting (as you need to put this data into the device so it can calculate the bolus dose)

Question 22

Define basal dose of insulin

Answer 22

provides a constant supply of insulin to bring down high resting blood glucose levels.

Usually given morning and night

Short-acting insulin

Question 23

Define bolus dose of insulin

Answer 23

Bolus is much more powerful but shorter-lived effect on blood sugar

Usually given before or after meals and in moments of extremely high blood sugar

Question 24

Describe how sensor augmented pump works?

Answer 24

• Involves one device to measure the glucose levels which sents the data to another device which delivers the insulin.
• It is useful in patients who suffer from hypoglycaemia
• It senses when levels of blood glucose reaches low and suspends insulin delivery to increase the blood glucose levels.