Type 1 diabetes Flashcards
What is LADA?
Latent autoimmune diabetes in adults - more older people are presenting with type 1 diabetes
What can diabetes present alongside?
following pancreatic damage and endocrine diseases like Cushing’s
What is monogenic diabetes?
caused by one gene e.g. MODY, mitochondrial diabetes (can features phenotypically as T2/T1 DM)
Which diabetes do the majority of patients suffer from?
Type 2
What causes type 1 diabetes?
An environmental influence + addition to genetic influences, can cause the destruction of beta cells. Usually autoimmune. Once this happens, the patient is insulin deficient, which leads to hyperglycaemia.
What causes type 2 diabetes?
In type 2 diabetes, there is a stronger genetic influence. It is associated with obesity, and patients develop insulin resistance. Eventually, patients become hyperglycaemic. In these patients, the pancreas works hard to produce a lot of insulin, but the body can’t use it. Eventually, the beta cells fail.
Which diabetes is ketoacidosis a feature of?
T1DM - caused by a lack of insulin in the body, which causes the body to break down fat for energy. Ketones are released into the body as the fat is broken down.
Describe the process of type 1 diabetes development
- There are environmental and genetic influences, that occur over time
- The patient gets pre-diabetes, followed by overt diabetes, as the beta cells start to malfunction
- Slow process
- Patients admit, sick from diabetic ketoacidosis
- Diabetes type 1 is a relapsing remitting disease
What is an important factor in type 1 diabetes?
Immune system - if you have one autoimmune condition you are more likely to get another. Risk of automimmunity in relatives
What can be measured in T1DM to differentiate from T2DM?
auto antibodies
In type 1 diabetes which cells are present?
lots of plasma cells and t cells (t cells involved in beta cell destruction)
How does the environment affect T1DM?
Higher prevalence of T1DM in the winter months, compared with the summer - could be a virus targeting beta cells during this time
Certain places around the world have a higher prevalence too
Give examples of antibodies that can be measured in T1DM?
- Islet cell antibodies (ICA)
- Insulin antibodies (IAA)
- Glutamic acid decarboxylase antibodies (GADA)
- Insulinoma-associated-2 autoantibodies (IA-2A)
(some people with T1DM don’t have antibodies)
What are the signs of diabetes?
- Dehydration
- Cachexia
- Hyperventilation
- Smell of ketones
- Glycosuria
- Ketonuria
What are the symptoms of diabetes?
- Polyuria
- Nocturia
- Polydipsia
- Blurring of vision
- Thrush
- Weight loss
- Fatigue
What happens to adipose tissue if you lack insulin?
Fatty acids in adipose tissue are broken down. Therefore triglycerides start to release lots of fatty acids. They are taken up by the liver and ketone bodies are made. These can be detected in the urine and blood. Some ketones can go to kreb’s cycle.
What happens to muscle during insulin deficiency?
proteins are released from muscle -> liver-> glucose production
What happens to glucose during insulin deficiency?
Glucose is released from liver into circulation, not taken up by muscle and causes hyperglycaemia
What are the aims of T1 diabetes treatment?
- Reduce early mortality
- Avoid acute metabolic decompensation
- Prevent long term complications (retinopathy, nephropathy, neuropathy, vascular disease)
- Type 1 diabetics need exogenous insulin to preserve life
What should the diet be like in T1DM?
- Reduce calories as fat
- Reduce calories as refined carbohydrate
- Increase calories as complex carbohydrate
- Increase soluble fibre
- Balanced distribution of food over course of day with regular meals and snacks
What are the two parts to insulin treatment?
with meals background insulin (basal production)
Is the insulin long or short acting with meals and background?
with meals - short
background - long
Give examples of insulin analogues with meals
lispro, aspart, glulisine
Is human insulin or an analogue given with meals?
both
What should the insulin maintain in T1DM?
basal insulin level
What are some background insulin analogue examples?
glargine, determir, degludec
What is the structure of backrgound insulin?
non c bound to zinc or protamine
What do patients inject themselves with when they eat and why?
long acting insulin - lasts patient till next meal
short acting insulin
Why are insulin analogues genetically modified?
to alter absorption, distribution. metabolism and excretion
What is an insulin pump?
A device that administers continuous insulin. The pump has pre-programmed basal rates and bolus for meals. The pump does not measure glucose – so there is no completion of the feedback loop. Used in patients with severe diabetes.
What is islet cell transplantation?
Some of the beta cells from the donor pancreas are taken, cells are isolated, and then injected into the liver. Through hepatic veins, these beta cells migrate around the body, and can then produce insulin..
How do we measure the success of diabetes treatment?
- Measure capillary glucose levels
- Monitor glucose levels in by taking a blood sample
- Measuring glucose is using a glucose monitor – measures glucose in real time
- A continuous glucose monitor can help with glucose control long term
How can HBA1c be used to measure glucose levels?
HbA1c is a blood sample that relies on red cells attaching to the glucose monitor
- HbA1c red cells react with glucose –> this is irreversible and non-covalent
- The lifespan of red cells is around 120 days, so this test gives us an idea of glucose levels over 3 months
- The rate of glycation is faster in some individuals
What does a high HBA1c mean?
more glucose
What happens to HBA1c accuracy in patients with thalasseamia, renal failure etc?
The red cell half life will be changed
What is ketoacidosis?
Patients are hyperglycaemic- Reduced tissue glucose utilisation and increased hepatic glucose production. A a result, patient has a metabolic acidosis - circulating ketone bodies
What is hypoglycaemia’s definition?
What happens if BG ,=<3?
What happens if BG <2?
<3.6 mmol/l
If blood glucose < 3 mmol/l: most mental processes will be impaired
If blood glucose < 2 mmol/l: consciousness is impaired
Why does hypoglycaemia occur in diabetes?
- Occasional hypoglycaemic episodes are inevitable as a result of treating diabetes
- Such episodes are a major cause of anxiety in patients & families
What is severe hypoglycaemia?
Any hypoglycaemic episode that requires the help of another person to treat it
What are the effects of hypoglycaemia on patients?
- Severe hypoglycaemia may contribute to arrhythmia and sudden death
- Hypoglycaemia may have long-term effects on the brain (cognitive problems, irreversible damage)
- Recurrent hypoglycaemic episodes result in a loss of warning – frightening
Who is at risk of hypoglycaemia?
Those with a lower quality of glycaemic control. Hypoglycaemia is more frequent in patients with low HbA1c
When and why doe hypoglycaemic episodes occur?
They can occur at any time, but often there is a clear pattern (e.g. pre-lunch episodes are common, nocturnal episodes are very common and often not recognised)
Patients may start going to the gym while not changing their insulin dose, patients may miss meals or have inadequate snacks, patients may drink lots of alcohol and Inappropriate insulin regime
Signs/symptoms of hypoglycaemia
Due to increased autonomic activation
- Palpitations (tachycardia)
- Tremor
- Sweating
- Pallor/cold extremities
- Anxiety
Due to impaired CNS function
- Drowsiness
- Confusion
- Altered behaviour
- Focal neurology
- Coma
How should hypoglyaemia be treated (oral)?
If the patient is conscious, feed the patient
- Give quick acting glucogels – rapidly absorbed as a solution or as tablets
- Complex CHO – to maintain blood glucose after initial treatment
How could hypoglycaemia be treated (parenteral)?
If the patient has impaired consciousness
- Intravenous dextrose (10%) glucose infusion
- 1mg glucagon (intramuscular)
- Avoid concentrated solutions (e.g. 50% glucose) – can cause severe skin reactions
How are patients taught to deal with hypoglycaemia?
They can be taught how to inject themselves when they are having a hypoglycaemia episode. However if you have been fasting for days the glycogen stores in the liver are depleted.
Importance of haplotypes in T1DM
Some HLA types have a higher genetic suscpetibility
HLA-DR3 and HLA-DR4 deletions pose a significant risk to chance of getting T1DM.
