type 1 diabetes Flashcards
What is type I diabetes?
Autoimmune condition where antibodies attack the pancreatic βcells which usually produce insulin and destroys them causing a partial or complete insulin deficiency
Can T1D present later in life? Can T2 present in childhood? What is diabetic ketoacidosis associated with?
T1D can present later in life, T2 can present in childhood due to rising obesity rates. Diabetic ketoacidosis usually in T1 but can happen in T2
What is MODY?
Monogenetic diabetes causes by a single genetic defect. Can present at T1 or 2
How does T1D usually develop
Usually it has genetic susceptibility but is precipitated by an environmental stimulus such as a viral infection. At first the autoantibodies attack causing a decline in b mass (asymptomatic phase) and when a lot of b mass is lost, hyperglycaemia. No c-peptide is detected towards the end.
What is C-peptide and why is it measured instead of insulin?
C peptide is a cleavage product of insulin and therefore reflects endogenous insulin. Cant measure insulin because they are usually on insulin injections.
What do immune cells attack in T1D?
autoantibodies attack the β-cells and there is immune infiltrations subsequently into the pancreatic islets. At one point the immune process burns out β cells and there is nothing left to attack
Why is immune basis of T1D importnant?
Because they have increased risk of other autoimmune diseases, risk of autoimmunity in family, more complete destruction of β cells and also have autoantibodies that can be detected
What is the immune basis of T1D?
Auto-antigen is presented to autoreactive CD4+ cells which activate CD8 cells which travel to β cells that express the autoantigen, and release pro-infalmmaotry cytokines as well. Dysfunction of regulatory T cells fail to suppress autoimmunity.
What is the genetic susceptibility of T1D associated with?
HLA - human leukocyte antigen.
What are environmental factors contributing to T1D?
Weather, seasonal variaration, infections, dietary changes, gut microbiota
What types of antibodies would be present in T1D and some examples?
Pancreatic autoantibodies eg. Insulin antibodies IAA, glutamic acid decarboxylase, insulinoma-associated -2 antibodies
What is the presentation of T1D?
Osmotic symptoms - nocturia, polyuria, polydyspsia. Blurring of vission because high glucose causes osmotic shifts in the eyeball. Recurrent infections. Weight loss, fatigue. Signs –> cachexia, dehydration, smell of ketones, glycosuria, ketonuria
What are the effects of insulin deficiency on the body?
Leads to lipolysis, proteinolysis, incrases hepatic glucose output, hyperglycaemia.
What are the aims of T1D treatment?
To maintain glucose levels without hypoglycaemia, to prevent acute metabolic decompensation and to prevent microvascular/macrovascular complications
What are complications of T1D?
Microvascular - retinopathy, neuropathy, nephropathy. Macrovascular - peripheral vascular disease, ischaemic heart disease, cerebrovascular disease. Hypoglycaemia due to treatment
What is the physiological profile of insulin normally?
Normally not zero, basal amount produced after meal large 1st phase insulin release peak and later on second peak smaller (second phase of insulin production)
What are different types of insulin?
- short acting insulin (with meals) - human (actrapid) or insulin analogue like lispro. 2. background basal long lasting insulin - bound to zinc or protamine or insulin analogue
What doses of each insulin should they be given daily?
Either 3 short acting + 1 long acting or 3 actrapid + 2x daily intermidate acting insulin
What is insulin pump therapy?
Insulin pump continuously delivers short acting insulin slowly into the subcutaneous space. Can programme it to deliver different amounts
What dietary advice should they be given?
Dose adjustment for carb content in foods. Replace refined carbs with complex carbs with a lower GI
What is a closed look/artificial pancreas? What is a disadvantage?
Device with a glucose sensor that monitors changes in glucose and an insulin pump to deliver the insulin. However there is a slight lag so that the pump is always acting on glucose levels 15 minutes prior so can be hard when accounting for large carb meals.
What are the 2 types of transplanation for T1D and what do they involve?
- islet cell tranplantation (islet cells are taken from donor and injected into abdomen) 2. simultaneous kindey & pancreas transplants - better survival graft if transplanted together - both require lifelong immunosupression
How to monitor glucose levels?(2)
- blood capillary prick test. 2. continous 24 hours glucose monitoring
What is HbA1C and what does it reflect? Limitations?
Glycated haemoglobin . Glucose can stick on hameoglobin. Reflects 3 months of glycaemia. Affected by thigns like anaemia, haemolysis, kidney disease. Cheap and widely available
What to do to guide insulin doses?
Clinically measure hbA1c every 3-4 months to know when to increase/decrease dose
What is diabetic ketoacidosis and when can it happen. When is diagnosis made?
It can happen during acute illness (increased GH and cortisol), missed insulin doses or inadequate doses. Diagnosis made if pH <7.3, increased ketones, bicarbonate <15mmol/L and glucose >11mmol/L
What is hypoglycaemia and why can it be problematic in T1? What are risks associated with it?
Hypoglycaemia is lower levels of glucose. Can be problematic because freuqent ones can develop a state where you don’t feel hypo effects and if left untreated can elad to seizure coma or death. Excessive frequency, being less aware of it, nocturnal, severe recurrent. Risks include seizure comma death, emotions, congiton, driving
Who is at risk of problematic hypoglycaemia?
Exercise, missed meals, alcohol, lower HbA1C lack of training
What are strategies for dealing with problematic hypoglycaemia?
Indication for insulin pump therapy. Different insulin analogues. Re-educated food wise
What is acute management of hypo if: alert & orientated? Confused but can swallow? Unconscious/cant swallow? Deteriorating/difficult IV access?
If alert orientated - give oral carbs eg juice/sweets/sandwich. If confused but can swallow give buccal glucose or glucogel. If unconscious cant swallow - give 20% glucose IV. If no IV give IM injected 1mg glucagon
