Type 1 Diabetes Flashcards
Define type 1 diabetes mellitus
Autoimmune disorder characterised by hyperglycaemia due to absolute insulin deficiency
Develops due to destruction of the insulin-producing beta cells of the Islets of Langerhans in the pancreas by the immune system
What are the two key characteristics of type 1 diabetes
Absolute insulin deficiency
State of persistent hyperglycaemia
When does type 1 diabetes typically present
Tend to develop in childhood/early adult life
Diabetic ketoacidosis (DKA) is usually a first presentation of which type of diabetes
T1DM
What is the name of the emergency condition associated with T1DM
Diabetic ketoacidosis (DKA)
What causes the development of T1DM
- Mechanism is not fully understood
- The underlying cause is thought to be a combination of genetics and environmental triggers e.g. Enterovirus
What produces insulin
Insulin is produced by the beta cells in the Islets of Langerhans in the pancreas
Insulin functions to:
a) lowers blood glucose level
b) raises blood glucose level
Insulin functions to lowers blood glucose level
Background levels of insulin are always there but there is a rise with a rise in blood sugar levels
Insulin acts to two-fold to reduced blood sugar.
What are these?
Tells cells of the body to absorb the glucose and use it as fuel
Stimulates glycogenesis i.e. formation of glycogen from glucose – in the muscles and liver
What is glycogenesis
formation of glycogen from glucose
Where is glycogen stored
In the muscles and liver
Where is glucagon produced
Hormone produced by the alpha cells in the Islets of Langerhans in the pancreas
Glucagon functions to:
a) lowers blood glucose level
b) raises blood glucose level
b) raises blood glucose level
Glucagon is used when glucose is gone
Glucagon functions to raise glucose levels
What are the two ways in which it raises blood glucose levels
Stimulates glycogenolysis i.e. the breakdown of glycogen stores into glucose
Stimulates gluconeogenesis i.e. the conversion of fat and protein into glucose in the liver
What is glycogenolysis
The breakdown of glycogen stores into glucose
What is gluconeogenesis
The conversion of fat and protein into glucose in the liver
When does Ketogenesis occur
Occurs when there is insufficient glucose supply and glycogens stores are exhausted
What is ketogenesis
The liver takes fatty acids and converts them to ketone acids (ketones).
What are ketones
Ketones are water soluble fatty acids that can be used as fuel.
They can cross the BBB and be used by the brain as fuel
The final product of ketogenesis - the conversion of fats into ketones
What are the triad of symptoms for diabetes
Polyuria
Polydipsia
Weight loss
What is polyuria?
Excessive production and passage of urine
What is polydipsia
Increased thrist
Why is intensive glycaemic control important?
Decrease the incidence of microvascular and macrovascular complications
Prevents emergency presentations e.g. DKA (T1DM), HHS (T2DM)
Name the three microvascular complications of diabetes
Retinopathy
Nephropathy
Neuropathy
Name three macrovascular complications of diabetes
Coronary artery
Cerebrovascular
Peripheral vascular disease
How can you measure ketones
In the blood or urine
The presence of C peptide can be useful to investigate T1DM.
What are C peptides
C peptide is an amino acid that is released at the same time as insulin from the pancreas
Name the three diabetes-specific autoantibody titres?
Anti-GAD (antibodies to glutamic acid decarboxylase)
ICA (Islet cells antibodies)
IAA (Insulin AutoAntibodies)
Name two potential short term complications of T1DM
Hypoglycaemia
DKA
What are the three components of the T1DM management
Patient education
Insulin therapy
Monitoring
Why should T1DM cycle their injection sites
To prevent lipodystrophy, condition in which the subcutaneous fat hardens which affects the absorption of insulin from that site.
Patients are able to monitor their blood glucose level by capillary blood glucose monitoring kits.
How many times a day are they recommended to check it
four times a day
HbA1c indicates the average blood glucose concentration over a three-month period.
What is the target level of HbA1c?
<= 48mmol/mol
Name the three types of insulin regimens
Basal-bolus
Mixed (biphasic) regimen
Continuous insulin infusion (insulin pump)
Which insulin regiment is 1st line
Basal-bolus – best mimics the physiology
Describe the basal bolus insulin regiments
Combination of long acting insulin for basal dosing and rapid-acting insulin for bolus dosing.
Correction dose may be added to the bolus insulin based on the pre-meal blood glucose level.
Offers flexibility to tailor insulin therapy with the carbohydrate load of each meal.
Describe the mixed (biphasic) insulin regiment
Use of both short-acting and intermediate-acting insulin
Can be a premixed product or the preparation can be mixed by the patient
Describe the continuous insulin infusion (insulin pump) insulin regiment
Supplies regular amount via rapid or short acting insulin, which is delivered by a programmable pump and insulin storage reservoir via a subcutaneous needle or cannula
Why sometiems after diagnosis are insulin levels low?
There may be some residual function of the beta cells
Insulin requirement may suddenly rise as the remaing beta cells are destroyed
