Diabetes Mellitus Type 1 and 2 Flashcards
What is the definition of type 1 diabetes mellitus?
Autoimmune destruction of the pancreatic beta-cells resulting in beta-cell deficiency and therefore absolute insulin deficiency
What are the two types of type 1 diabetes?
1A (immune mediated)
- most common
- environmental trigger in genetically susceptible individual mediated by autoimmune process within pancreatic B cell
1B (idiopathic)
- permanent insulinopenia but no evidence of B cell dysfunction or autoantibodies
- prone to DKA
- minority of T1DM (~5%)
- mostly African or Asian ancestry
- strongly inherited
What are the risk factors for type 1 diabetes mellitus?
Age (peak diagnosis 10-14 years)
Genetic susceptibility and inheritance (DR3-DQ2 and DR4-DQ8)
Environmental factors
- gestational infection and older age
- viral infections (enteroviruses)
- childhood obesity
- psychological stress
- environmental toxins (alloxan)
- early introduction to cow’s milk and vitamin D deficiency
What is the pathophysiology behind type 1 diabetes?
- Genetic susceptibility
- Environmentaltrigger
- T-cell mediated autoimmuneresponsewith production of autoantibodies that target and destroy β-cells
- Absolute insulindeficiency causing elevatedblood glucose levels
What are the clinical features of type 1 diabetes?
Usually acute onset
Polyuria
Polydipsia
Weight loss
What are some investigations for type 1 diabetes?
Fasting glucose ≳ 7.0mmol/l with symptoms
OR
Random glucose ≳ 11.1mmol/l with symptoms
GAD/IA2 antibodies and C peptide sometimes done
NOT HbA1c (used for monitoring)
What are the management options for type 1 diabetes?
Insulin
Education and self monitoring
Annual review assessment
Pancreas transplant
What does insulin treatment for type 1 diabetes involve?
- Usually basal (long-acting once daily) bolus (short-acting with meals) regimen to mimic normal endogenous insulin production
- MDI (3-4x injections per day) or CSII
- Most use insulin analogues to reduce hypoglycaemia risk
- Rotate injection site to avoid lipohypertrophy
What does the annual review of type 1 diabetes involve?
Weight
Blood pressure
Bloods: HbA1c, renal function and lipids
Retinal screening
Foot risk assessment
Record severe hypoglycaemic episodes or admission with DKA
What are the two types of pancreas transplantation?
Islet transplantation
- harvested from cadavers and injected into portal vein where they seed into the liver
- reserved for severe episodes of severe hypoglycaemia, and uncontrolled diabetes/severe complications despite maximal treatment
- 50-70% achieve insulin independence after 5 years
Whole pancreas transplantation
- Usually people with T1DM and end-stage kidney disease at the same time as kidney transplant
What is the definition of type 2 diabetes mellitus?
Combination of severe insulin resistance and less severe insulin deficiency
What type of diabetes is more common?
T2DM (90-95%)
What are some risk factors for type 2 diabetes?
Age >45 years due to declining B cell function
Genetics
Ethnicity (South Asian, African, Afro-Caribbean)
Obesity, poor diet and physical inactivity
What is the pathophysiology behind type 2 diabetes?
Insulin resistance and decreased uptake of insulin by GLUT channels
Decreased insulin production
What are some clinical features of type 2 diabetes?
Gradual onset, majority asymptomatic
Thirst
Polyuria
Blurred vision
Weight loss
Recurrent infections
Tiredness
Acanthosis nigricans
