Lecture 3: T1DM Flashcards
What are the three tests used to diagnosis diabetes mellitus?
- Fasting blood glucose
- 75g oral glucose tolerance test
- HbA1c
What is the criteria to diagnosis diabetes mellitus?
Needs 2 abnormal tests or 1+ symptoms
What are the levels of blood glucose in the fasting blood glucose test that indicate diabetes?
< 6.0mmol/l: normal
6.1-6.9mmol/l: impaired
> 7mmol/l: diabetes
What are the levels of blood glucose in the oral glucose tolerance test that indicate diabetes?
< 7.7mmol/l: normal
7.8-11mmol/l: impaired
> 11.1mmol/l : diabetes
Which diagnostic test is the gold standard for diagnosing diabetes mellitus?
HbA1c
Name the different types of diabetes?
- Categories in relation to their cause
- Type 1 (prevalence 0.5%)
- Type 2 (prevalence 5%)
- Maturity-Onset Diabetes of the Young (MODY)
- Gestational
- Secondary
Define secondary diabetes?
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
What classes of diabetes can be described as insulin deficient
Those that are characterised by lacking insulin
- Type 1 diabetes
- MODY
- Pancreatitis
- Cystic fibrosis
What classes of diabetes can be described as insulin resistant
Those that are characterised by the inability of the body to react to insulin
- Type 2 diabetes
- Gestational
- Steroid-induced
Which auto-antibodies are associated with Type 1 diabetes
- Islet cell antibody (ICA)
- I-A2
- Insulin auto-antibody (IAA)
- GAD65
- ZnT8
Which susceptible genes are associated with type 1 diabetes
- HLA eg DR3/4 – DR2/8
- Insulin (VNTR)
- PTPN22
- IL2RA
- CTLA-4
- IFIH1
HLA system is a gene complex encoding the___ proteins
The major histocompatability complex (MHC)
Diabetes mellitus is associated with what other conditions?
Other autoimmune diseases eg
- Thyroid disease
- Coeliac disease
- Addison’s disease
- Inflammatory bowel disease (IBD)
- Premature ovarian failure
Into which layer is insulin injected into
The subcutaneous layer
Which gene is the most common of mongeneic diabetes
HNF-1 alpha (60%)
Explain the aetiology of monogenic forms of diabetes
- 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%)
Describe neonatal diabetes?
- 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
Which diabetes is diagnosed under 6 months?
Neonatal diabetes
Type 1 diabetes doesn’t affect anyone under 6 months.
What are the two main forms of monogenic diabetes?
Some rare forms of diabetes result from mutations or changes in a single gene
- Neonatal Diabetes Mellitus
- MODY
Neonatal diabetes tested for in all patients diagnosed with diabetes under what age?
9 months old
What does a diabetic pump do
- 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)
Define basal dose of insulin
provides a constant supply of insulin to bring down high resting blood glucose levels.
Usually given morning and night
Short-acting insulin
Define bolus dose of insulin
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
Describe how sensor augmented pump works?
- 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.
