Diabetes Flashcards
What is diabetes?
An elevation of blood glucose above a diagnostic threshold
How is the diagnostic threshold for diabetes decided?
The blood glucose level at which a person’s risk pf developing retinopathy increases substantially
What are the different criteria for diagnosing diabetes?
Random or 2 hour glucose >11.1
OR a fasting glucose of >7 mmol/L
OR an HbA1c >48 mmol/mol
Needs confirmatory test if patient is asymptomatic
How is the diagnostic criteria for gestational diabetes different from other types of diabetes?
The threshold is lower as it is based on risk to the foetus, not risk of developing retinopathy
How is C-peptide useful for monitoring diabetes?
It is a measure of insulin secretion
If a patient has had an injection of insulin, measuring insulin won’t be representative of the inulin secretion so C-peptide can be measured as it is secreted along with insulin so gives indication of insulin secretion
How can types of diabetes be classified?
Disorders of beta cells (insulin secretion)
Disorders of insulin action
Mixed - T2DM
What are some disorders of insulin secretion?
T1DM
MODY (Maturity Onset Diabetes of the Young)
Pancreatic disease
What are some disorders of insulin action?
Donohue syndrome
NAFLD
Cushing’s
Steroid induced
What is type 1 diabetes?
Autoimmune destruction of the pancreatic beta cells resulting in beta cell deficiency
What is type 2 diabetes?
Insulin resistance and insulin deficiency
Kind of a diagnosis of exclusion - not type 1 and not any other cause
What are the differences between type 1 and 2 diabetes?
T1 usual onset is young and T2 is usually middle age and elderly (but both can occur in any age)
T1 not associated with being overweight, where T2 is (but not always)
T1 is autoimmune, T2 is not
T1 requires insulin treatment, T2 doesn’t usually
What are the symptoms of high blood glucose?
Polyuria Thirst and polydipsia Blurred vision Genital thrush Fatigue Weight loss
What are the symptoms of retinopathy?
Loss of vision
Retinal bleed
Retinal changes found by optician
What are the complications of diabetes?
Retinopathy Neuropathy Nephropathy High blood pressure Dyslipidaemia MI/ACS Stroke Peripheral vascular disease Cognitive dysfunction/dementia
What is HbA1c and why is it useful?
Glycated haemoglobin
Haemoglobin exposed to glucose becomes glycated
Red blood cells survive for about 90 days so HbA1c gives measure of glucose exposure over the last 90 days
What is HbA1c now measured in, and what did it used to be measured in, and how do you convert?
Now - mmol/mol
Old - %
7%=53mmol/mol
+1% = +11mmol/mol
How is HbA1c used in clinical practice?
To monitor diabetes
What is the aim for HbA1c level?
<53mmol/mol (7%)
What is the treatment algorithm for T2 diabetes?
Diagnosis Therapeutic lifestyle change (can go into remission) Monotherapy Combination therapy without insulin Combination therapy with insulin
What is the main dietary advice for patients diagnosed with T2 diabetes?
Normal intake of unrefined carbohydrates, reduction of refined sugar intake
Reduce fat intake
Increase fruit and veg
Reduce salt
What are the main drugs used in the treatment of T2DM?
Metformin Sulphonylureas Thiazolidinediones (TZDs) Incretin drugs (DPP4 inhibitors and GLP-1 receptor inhibitors) SGLT2i
What screening is done for diabetes complications?
Digital retinal screening
Foot risk assessment
Urine albumin:creatinine ratio, creatinine levels
How does HbA1c affect the rate of complications?
As HbA1c increases, risk of complications increases
An 11mmol/mol reduction in HbA1c means 37% decrease in complication risk
How does hyperglycaemia result in complications?
Glucose is not being completely oxidised by glycolysis and mitochondrial metabolism (TCA)
Glucose is therefore broken down by alternative pathways.
These alternate pathways cause osmotic damage, inflammation, fibrosis and increases reactive oxygen species
This causes damage and complications
What are the main microvascular complications?
Retinopathy
Nephopathy
Neuropathy
What eye pathologies do people with diabetes get?
Diabetic retinopathy Diabetic macular oedema Cataracts Glaucoma Acute hyperglycaemia (blurred vision)
What are cataracts?
Clouding of the lens (earlier complication)
What is glaucoma?
Increase in fluid pressure in the eye leading to optic nerve damage
What are the foeva and macula?
The site where most of the rods and cones are concentrated