Type 2 diabetes mellitus Flashcards
What is diabetes mellitus?
A state of chronic hyperglycaemia sufficient to cause long-term damage to specific tissues, notably the retina, kidney, nerves and arteries.
What is the normal fasting blood glucose level?
<6mmol/L.
What is the normal 2 hour blood glucose level in a 75g oral glucose tolerance test?
<7.8mmol/L.
What is the normal random blood glucose level?
<11.1mmol/L.
What are the parameters that define diabetes mellitus?
Fasting blood glucose >7mmol/L.
2 hour blood glucose >11.1mmol/L.
Random blood glucose >11.1mmol/L.
What are the numerical boundaries of impaired fasting glucose?
6.0-7.0mmol/L.
What are the numerical boundaries of impaired glucose tolerance?
7.8-11.1mmol/L.
What do impaired fasting glucose and/or impaired glucose tolerance show?
Greater risk of macrovascular risk- at risk of progressing to higher sugar, but doesn’t yet have diabetes or microvascular risk.
Discuss the pathophysiology of T2DM.
MODY relatively uncommon but gives useful metabolic insights.
Genes and intrauterine environment and adult environment.
Insulin resistance and insulin secretion defects.
Fatty acids important in pathogenesis and complications- contribute to damage to beta cells and insulin resistance.
What is MODY?
Maturity onset diabetes of the young.
Several hereditary forms (1-8).
Autosomal dominant.
Ineffective pancreatic B cell insulin production.
Mutations of transcription factor genes, glucokinase gene.
Positive family history, no obesity.
Specific treatment for type.
What are the mechanisms of T2DM?
Mostly genetic disorder, behaving as autosomal dominant- don’t know the genes, not a single gene disorder.
Genes contribute to insulin resistance through adult life and probably through childhood.
Adipocytokines are a mechanism of diabetes.
Genes for diabetes associated with IUGR.
Genes associated with obesity and handling of fatty acids- part of mechanism.
Insulin resistance associated with metabolic complications like dyslipidaemia.
Metabolic and mitogenic complications due to insulin resistance lead to macrovascular complications.
Patient slowly fails to make enough insulin- B cell failure leading to hyperglycaemia and metabolic dyslipidaemia.
Inflammatory effects of insulin resistance.
Hyperglycaemia leads to microvascular complications.
B cell failure may become absolute- insulin requirement.
How does T2DM present?
Heterogeneous. Obesity. Insulin resistance and insulin secretion deficit. Hyperglycaemia and dyslipidaemia. Acute and chronic complications.
What is the simplest clinical measurement that can be taken to predict risk of ischaemic heart disease?
Waist circumference.
What percentage of T2DM patients are obese?
80%.
How may perturbations in gut microbiota be linked to T2DM?
Obesity, insulin resistance T2DM.
Host signalling.
Bacterial lipopolysaccharides fermentation to short chain fatty acids, bacterial modulation bile acids.
Inflammation, signalling metabolic pathways.
Most studies correlative.
Which diabetes drug is not associated with weight gain?
Metformin.
How do patients present with T2DM?
Osmotic symptoms, e.g. polyuria, polydipsia.
Infections.
Screening test.
At presentation of complication: acute, e.g. hyperosmolar coma, or chronic, e.g. ischaemic heart disease, retinopathy.
What are the microvascular complications of T2DM?
Retinopathy.
Nephropathy.
Neuropathy.