Diabetes Flashcards
What is Diabetes Mellitus?
A syndrome of chronic hyperglycaemia due to a relative insulin deficiency, resistance or both
What should normal blood glucose levels be under all conditions?
3.5- 8.0mmol/L
What is the principal organ of homeostasis?
The liver
In what ways does the liver control glucose levels?
- Stores and absorbs it
- performs gluconeogensis
- performs glycogen’s if blood glucose is too high
- Lipogenesis
What does the liver do if the blood glucose levels are too low?
Splits glycogen converting it to glucose in a process called gluconeogensis
How much glucose if produced and utilised a day?
200g
Which organ is the main consumer of glucose?
The brain
Why can the brain now use free fatty acid conversion into ketone bodies for energy?
Free fatty acids can’t cross the BBB
Is glucose uptake in the brain dependent on insulin?
No
What is the function of insulin?
- Suppresses hepatic glucose output
- Increases glucose uptake into insulin sensitive cells
What does biphasic insulin release mean?
First phase is rapid release when the b cells sense the rising glucose levels.
Second phase is if the levels remain high
What does glucagon do?
- Increases hepatic glucose output
- Reduces peripheral glucose update
- Stimulates: Lipolysis and muscle glyconeolysis and breakdown
What is C peptide?
It joins together the alpha and beta chains in proinsulin which is the precursor to insulin
What happens in regards to C peptide when insulin is being produced?
There ends up being high levels of C peptide in the blood due to the fact that proinsulin is cleaved from its c peptide.
After secretion where is insulin carried to?
The liver
Briefly describe how glucose enters a cell?
It is carried through by a family of specialised glucose-transporter proteins that bind with the surface of the cell when activated by insulin.
What are the two types of primary diabetes?
Type 1 and Type 2
What conditions can diabetes be secondary to?
- Pancreatitis
- Trauma/pancreatectomy
- Neoplasia of pancreas
- Acromegaly
- Cushing syndrome
- Addisons
- Drugs
What are the macro vascular complications associated with diabetes?
- Atherosclerosis
- Peripheral vascular disease
What are some symptoms of peripheral vascular disease?
- Intermittent claudication
- Rest pain (pain when sleeping and having to walk around to get the blood flowing)
What microvascular problems are associated with diabetes?
- Diabetic retinopathy
- Diabetic nephropathy
- Diabetic neuropathy
- Infections
- Diabetic foot ulceration
What is seen in diabetic retinopathy?
- Microaneuryms
- Haemorrhages
What is hallmark sign of diabetic nephropathy?
Proteinuria
What happens in diabetic nephropathy?
Thickening of the basement membrane of the glomerulus due to poor glycemic control will lead the microalbuminuria
How is microalbuminuria identified?
Urine albumin:creatinine ratio >3 – a conventional dipstick won’t work
What is the main worry with nephrotic syndrome?
It may process to end stage kidney disease and dialysis might be required
What is the commonest form of diabetic neuropathy?
Distal symmetrical ‘glove and stocking’
What are the features of diabetic neuropathy?
- Pain
- Autonomic dysfunction e.g postural hypertension
- Insensitivity e.g glove and stocking - can lead to food ulcerations
- Amyotrophy - painful asymmetrical wasting of quads and diminished knee reflex
- Mononeuritis - Isolated palsies mainly to extraoccular muscles
What is the treatment for diabetic neuropathy?
- Good glycemic control and opioids for the pain
How should diabetic neuropathy be managed?
Foot screening and teaching patients to care for their feet and check them everyday
What is type 1 diabetes mellitus?
Disease of insulin deficiency usually caused by autoimmune destruction of beta cells of the pancreas
What is the cause of type 1 diabetes?
Autoimmune - auto-antibodies forming against insulin and islet beta cells
Some genetic susceptibility - HLA-DR3-DQ2 or HLA-DR4-DQ8
Why are type 1 diabetics at risk of ketoacidosis?
Reduced glucose supply and so fatty acid oxidation is used for energy - this leads to ketone body production. These are acidic
What effect does acidification have on the blood?
Impairs the ability of haemoglobin to bind to oxygen
If a patient is in diabetic ketoacidosis what will their breath smell like?
Pear drops
What serious side effects do you get in a patient who is in ketoacidosis?
- Excess fat breakdown leading to weight loss and anorexia
- Dehydration leading to AKI
- Hyperglycaemia
What is diabetes mellitus type 2?
Results from a combination of insulin resistance and less severe insulin deficiency
What is the brief pathophysiology of DMT2?
Hypersecretion of insulin by the beta cells in response to the cells being resistant to insulin hyperglycaemia and lipid excess are toxic to beta cells and thus there is deterioration of beta cells.This leads to a progression towards insulin deficiency which can then require insulin therapy
Why don’t type 2 diabetics develop ketoacidosis?
Due to the small amount of circulating insulin in the blood which can halt the breakdown of fat and muscle into ketones.
