Type 1 Diabetes Mellitus incl. DKA Flashcards
How do people with T1DM typically present?
- skinny / lean
- young
- DKA
What is the cause of T1DM?
- environmental trigger (e.g. viral, bacterial infection) -> more new cases in the winter
- AI destruction of cells
- Insulin deficiency
- Genetics
What are symptoms of diabetes?
polyuria nocturia polydipsia blurring of vision ‘thrush’ (candida infection) weight loss fatigue
What are signs of diabetes?
dehydration cachexia hyperventilation (kussmaul respiration due to metabolic acidosis) smell of ketones glycosuria ketonuria
What are some forms of T1DM?
- LADA (latent autoimmune diabetes in adults)
- MODY (monogenic diabetes mellitus can present with features of types one and types 2)
Why is the immune basis of T1 diabetes important?
- Increased prevalence of other autoimmune disease (e.g. Addison’s, b12 problems)
- Risk of autoimmunity in relatives
- More complete destruction of B-cells
- Auto antibodies can be useful clinically
- Immune modulation offers the possibility of novel treatments
What is the role of genetics in diabetes?
- There is a genetic link
- certain HLA markers are linked to an increased T1 diabetes risk.
What are some markers in T1DM?
- Islet cell antibodies (ICA)- grp O human pancreas
- Insulin antibodies (IAA)
- Glutamic acid decarboxylase (GADA) – widespread nuerotransmitter
- Insulinoma-associated-2 autoantibodies (IA-2A)-receptor like family
T1DM patients have higher levels of these.
What are the most important tissues in the metabolism of glucose?
- muscle
- liver
- adipose tissue
What are the aims in treatment of T1DM?
- reduce early mortality
- avoid acute metabolic decompensation
What are long term complications of T1DM?
- retinopathy
- nephropathy
- neuropathy
- vascular disease
Can lead a pretty good life but are more at risk of stroke, MI and peripheral arterial disease
What is the recommended diet 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
- eating simple sugars makes it difficult to regulate glucose levels, even with insulin.
What is the insulin release pattern in healthy individuals?
- peaks when eating
- also there is basal insulin and glucose
What is insulin treatment like?
a) With meals
- short acting
- human insulin
- insulin analogue (Lispro, Aspart, Glulisine)
b) Background insulin
- long acting
- Non-c bound to zinc or protamine
- Insulin analogue (Glargine, Determir, Degludec)
They have to take short acting insulin with meals and also take long acting baseline insulin.
Also: Genetic engineering to alter absorption,
distribution, metabolism and excretion
Insulin Pump
- Continuous insulin delivery
- Preprogrammed basal rates and bolus for meals
- Does NOT measure glucose, no completion of feedback loop
- it gives basal insulin and you can programme it to give insulin after meals.
- there are problems with financing it
Islet cell transplants
- only been done a few times in the UK
- have to take immunosuppressant drugs for the rest of their life
- have to have very sever hypoglycaemia
- Islets of langerhans into the portal vein
How can you test if the treatment is working?
- monitoring capillary glucose
- not as accurate as venous glucose
- gives you a trend of levels throughout the day
What is CGM?
- continuous glucose monitoring
- gives a better feel of someones glucose and insulin levels throughout the day
HbA1c levels
- HbA1c red cells react with glucose, as it does with all proteins. Irreversible, non-covalent depends on;
- Lifespan of red cell, about 120 days
- Rate of glycation, faster in some individuals
- Hb opathy, renal failure etc
- Level of glucose
- Forms ideal measure of long term glycaemic control and has been shown to be related to risk of complications.
- Furthermore lowering HbA1c associated lower risk of complication particularly microvascular complication
in patients with SCD or thalassemia it may not be the best measurement, their RBCs have a shorter lifespan.
What are acute complications in T1DM?
- hyperglycaemia (reduced tissue glucose utilisation; increased hepatic glucose production; high glucose production due to lack of insulin.
- metabolic acidosis (circulating acetoacetate & hydroxybutyrate; osmotic dehydration and poor tissue perfusion)
Does all diabetic ketoacidosis occur in T1DM?
No, can also occur in other types
“hypos”
- occasional hypos inevitable as a result of treating diabetes
- major cause of anxiety in patients & families
- source of major misconceptions in media
- Big problem: patients tend to have a high glucose level because they try to avoid hypos.
Definitions
- hypoglycaemia - plasma glucose of < 3.6 mmol / l
- severe hypoglycaemia - any hypo requiring help of another person to treat
What are symptoms during a hypoglycaemic event?
- Disorientation, sweatiness, confusion
- can lead to a coma
- most people become aware, eat something and try to control it.
most mental processes impaired at <3 mmol/l
consciousness impaired at <2 mmol/l
severe hypoglycaemia may contribute to arrhythmia and sudden death
may have long-term effects on the brain
recurrent hypos result in loss of warnings
‘hypoglycaemia unawareness’
Hypo unwareness
If you have a lot of themy ou might not have all the symptoms and become unawawre, changes in the autonomic drive leads to loss of awareness.
Who is likely to have a hypoglycaemic events?
- main risk factor is quality of glycaemic control
- more frequent in patients with low HbA1c
When are hypoglycaemic events likely to occur?
- can occur at anytime but often a clear pattern
- pre-lunch hypos common
- nocturnal hypos very common and often not recognised
- pre dinner is quite common as well
Why do hypos occur?
- unaccustomed exercise (you should eat more when you exercise)
- missed meals
- inadequate snacks
- alcohol (when you go out drinking you might forget to inject insulin)
- inappropriate insulin regime
What are signs and symptoms of hypoglycemia?
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 due you treat hypoglycaemia?
Oral:
- feed the patient!!
- glucose
- rapidly absorbed as solution or tablets
complex CHO
- to maintain blood glucose after initial treatment
Parenteral:
- give if consciousness is impaired
- IV dextrose e.g 10% glucose infusion
- 1mg Glucagon IM
- avoid concentrated solutions if possible (e.g 50% glucose)
Glucagon
A hormone that causes glucose release from the liver
Would you give glucagon to a cachexia patient?
No because if they are very skinny and have fasted for a few days their glucose stores in the liver will have become very low sop the glucagon would not work -> you should give glucose i.v.
