pathophysiology and treatment of type 1 diabetes Flashcards
what is T1D called that presents later in life?
latent autoimmune diabetes in adults (LADA)
T1D is an autoimmune condition- why is this important?
Increased prevalence of other autoimmune disease
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 are the markers for T1D?
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
symptoms for T1D
polyuria nocturia polydipsia blurring of vision ‘thrush’ weight loss fatigue
Signs for T1D
dehydration cachexia hyperventilation smell of ketones glycosuria ketonuria
aims of treatment in type 1 diabetes
Reduce early mortality
Avoid acute metabolic decompensation
Type 1 diabetics need exogenous insulin to preserve lifeKetones define insulin deficiency
what long term complications arise from T1D?
- retinopathy
- nephropathy
- neuropathy
- vascular disease
what diet should be aimed in T1D?
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 is the insulin like with meals?
Short acting
Human insulin
Insulin analogue (Lispro, Aspart, Glulisine)
what is the background insulin given like?
Long acting
Non-c bound to zinc or protamine
Insulin analogue (Glargine, Determir, Degludec)
what does the insulin pump do?
Continuous insulin delivery
Preprogrammed basal rates and bolus for meals
Does NOT measure glucose, no completion of feedback loop
other methods of treating insulin deficiency
islet cell transplants
how do we know the treatment is successful?
capillary monitoring
how can HbA1c be used for glycaemic control?
low HbA1c = less sugar
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
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
what are some acute complications in T1D?
hyperglycaemia
reduced tissue glucose utilisation, increased hepatic glucose production
metabolic acidosis
circulating acetoacetate & hydroxybutyrate
osmotic dehydration and poor tissue perfusion
causes for acute complications in T1D?
new presentation
insulin omission
infection / other illness
what is hypoglycaemia?
what is severe hypoglycaemia?
hypoglycaemia - plasma glucose of < 3.6 mmol / l
severe hypoglycaemia - any hypo requiring help of another person to treat
key glucose concentrations for hypoglycaemia?
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’
who is at most risk for hypos?
- main risk factor is quality of glycaemic control
- more frequent in patients with low HbA1c
when do hypos occur most likely?
- can occur at anytime but often a clear pattern
- pre-lunch hypos common
- nocturnal hypos very common and often not recognised
why can hypos occur?
unaccustomed exercise missed meals inadequate snacks alcohol inappropriate insulin regime
Hypoglycaemia symptoms & signs
-due to increased autonomic activation
palpitations (tachycardia) tremor sweating pallor / cold extremities anxiety
Hypoglycaemia symptoms & signs
-due to impaired CNS function
drowsiness confusion altered behaviour focal neurology coma
how do you treat someone with hypoglycaemia?
2 types
ORAL
feed the patient!
glucose
- rapidly absorbed as solution or tablets
complex CHO
- to maintain blood glucose after initial treatment
PARENTERAL give if consciousness impaired IV dextrose e.g 10% glucose infusion 1mg Glucagon IM avoid concentrated solutions if possible (e.g 50% glucose)
main difference between T1D and T2D
T1D has ketones present, as T2D makes enough insulin to prevent ketone production
