Type 1 Diabetes Flashcards
(34 cards)
What is type 1 diabetes?
A metabolic disorder characterised by hyperglycaemia due to absolute insulin deficiency
Briefly describe the pathophysiology of type 1 diabetes
Due to destruction of pancreatic beta cells mostly by immune-mediated mechanisms
What are the risk factors for type 1 diabetes?
- Geographic region
- Genetic predisposition
- Infectious agents
- Dietary factors
What are the signs of type 1 diabetes?
- Tachypnoea
What are the symptoms of type 1 diabetes?
- Polyuria
- Polydypsia
- Unexplained weight loss
- Blurred vision
- Nausea and vomiting
- Abdominal pain
- Lethargy
What age group is most commonly diagnosed with type 1 diabetes?
Usually presents in childhood or adolescence→ typical age 5 to 15 years
What investigations should be ordered for type 1 diabetes?
- Random plasma glucose
- Fasting plasma glucose
- 2-hour plasma glucose
- Plasma or urine ketones
- HbA1c
Why investigate random plasma glucose? And what may this show?
- Confirms diagnosis in the presence of symptoms of polyuria, polydipsia, and unexplained weight loss
- ≥11 mmol/L
Why investigate using fasting plasma glucose? And what may this show?
- ≥6.9 mmol/L
Why investigate using 2-hour plasma glucose? And what may this show?
- ≥11 mmol/L
Why investigate using plasma or urine ketones? And what may this show?
- In the presence of hyperglycaemia suggest type 1 diabetes also assess for diabetic ketoacidosis
- Medium or high quantity
Why investigate using HbA1c? And what may this show?
- Reflects degree of hyperglycaemia over the preceding 3 months
- ≥48 mmol/mol (≥6.5%)
Which definitive test can be used to differentiate between type 1 or type 2 diabetes? And why?
C-peptide is a byproduct formed when pro-insulin is processed to insulin. Therefore, its levels reflect insulin production. Half life of C-peptide is 3 to 4 times longer than that of insulin.
Low or undetectable C-peptide level indicates absence of insulin secretion from pancreatic beta cells.
Briefly describre the treatment for type 1 diabetes
- 1st line: basal-bolus insulin regime
- Adjunct: pre-meal insulin correction dose
- Adjunct: amylin analogue
- 2nd line: fixed insulin regime
What is the target HbA1c? And why is this important?
HbA1c level of 48 mmol/mol (6.5%) or lower to minimize the risk of long-term vascular complications
How often should HbA1c be measured?
Every 3-6 months
What are the complications of type 1 diabetes?
- Diabetic Ketoacidosis (DKA)
- Hypoglycaemia
- Retinopathy
- Diabetic kidney disease
- Peripheral or autonomic neuropathy
- Cardiovascular disease
What differentials should be considered in type 1 diabetes?
- Type 2 diabetes
How does type 1 diabetes and type 2 diabetes differ?
- Differentiating signs and symptoms: typically, signs of insulin resistance (such as acanthosis nigricans) should be sought and in their absence clinical suspicion of type 1 diabetes is greater. Signs of more marked insulin deficiency (for example, glycaemic lability as well as susceptibility to ketosis) raise suspicion of type 1 diabetes. Older age and slow onset, obesity, a strong family history, absence of ketoacidosis, and initial response to oral anti-hyperglycaemic drugs are typical of type 2 diabetes.
- Differentiating investigations: C-peptide present and autoantibodies absent.
How should cardiovascular risk be managed in type 1 diabetes?
Assess the following cardiovascular risk factors annually:
- Lifestyle (including smoking status)
- Waist circumference
- Blood glucose control
- BP
- Albuminuria
- Full lipid profile
- Family history of CVD
Should aspirin be offered for prevention of CVD in type 1 diabetes?
Do not routinely offer aspirin for the primary prevention of CVD. Decisions about antiplatelet treatment will usually be made by, or in consultation with, secondary care.
What is the threshold BP for starting anti-hypertensives if no albuminuria or features of the metabolic syndrome are present?
The threshold for starting antihypertensive treatment in an adult with type 1 diabetes is blood pressure greater than or equal to 135/85 mmHg.
What is the first line treatment for hypertension in type 1 diabetes?
Renin-angiotensin system blocking drugs:
- Offer an angiotensin-converting enzyme (ACE) inhibitor, provided there are no contraindications
- If an ACE inhibitor is not tolerated, offer an angiotensin-II receptor antagonist (AIIRA) if appropriate
Briefly describe the use of lipid modification therapy in type 1 diabetes
Do not use a risk assessment tool to assess cardiovascular disease (CVD) risk in people with type 1 diabetes.
- For people with type 1 diabetes who do not have established CVD→ offer statin treatment with atorvastatin 20 mg for the primary prevention of CVD if the person:
- Is older than 40 years of age;
- Has had diabetes for more than 10 years;
- Has established nephropathy;
- Has other CVD risk factors (such as obesity and hypertension).
- For people with type 1 diabetes who have established CVD→ advise statin treatment with atorvastatin 80 mg for the secondary prevention of CVD.
