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
What are some investigations for type 2 diabetes?
One of the following in symptomatic people, or two in asymptomatic:
- Random blood glucose ≥ 11.1mmol/l
- Fasting plasma glucose ≥ 7mmol/l
- 2-hour glucose tolerance ≥ 11.1mmol/l
- HbA1C ≥ 48mmol/mol (6.5%)
BP
Ketones if random blood glucose >15mM
Cholesterol
Pancreatic autoantibodies
What is the management of type 2 diabetes?
Lifestyle changes (10-15% weight loss)
Medical management
What is the medical management algorithm for type 2 diabetes?
1) Metformin and lifestyle change
+ GLP-1 receptor antagonist for patients with atherosclerotic CVD
+ SGLT2i for patients with heart failure or CKD
2) Add one of: DPP-4i, SUs, TZDs
3) Consider insulin
What is a reasonable HbA1c target for type 2 diabetes?
7.0% (53mmol/mol)
What are some complications of diabetes?
Microvascular:
- Retinopathy
- Neuropathy
- Nephropathy
Macrovascular:
- MI/ACS
- Stroke
- PVD
How are macrovascular complications of diabetes prevented?
Cholesterol control
BP control
Antiplatelet therapy
What are the sick day rules for insulin use?
Don’t stop taking insulin even if not eating
Monitor blood glucose more frequently
Drink more fluids
