Diabetes Flashcards
What is the ideal blood glucose conc?
4.4-6.1 mmol/l
Where is insulin produced?
Beta cells in the Islets of Langerhans in the pancreas
What is insulin?
An anabolic hormone
Insulin reduces blood sugar levels in what 2 ways?
1) Causes cells in body to ABSORB glucose from blood and use it as FUEL
2) Causes muscle & liver cells to ABSORB glucose from blood and STORE it as GLYCOGEN
How does a lack of insulin affect glucose levels?
Hyperglycaemia (as cells cannot take up and use glucose)
Where is glucagon produced?
Hormone produced by the alpha cells in the Islets of Langerhans in the pancreas
Is glucagon an anabolic or catabolic hormone?
Catabolic (breakdown)
What is glucagon released in response to?
a) low blood sugar levels
b) stress
Glucagon INCREASES blood sugar levels in what 2 ways?
1) glycogenolysis –> tells liver to break down stored glycogen into glucose
2) gluconeogenesis –> tells liver to convert proteins & fats into glucose
What is T1D?
An autoimmune metabolic disorder in which the immune system targets and destroys the insulin-producing cells of the pancreas.
Without insulin, the cells of the body cannot absorb glucose from the blood and use it as fuel.
Therefore, the cells think there is no glucose available. Meanwhile, the glucose level in the blood keeps rising, causing hyperglycaemia.
What is T1D characterised by?
Persistent hyperglycaemia (random plasma glucose >11mol/L) due to defects in insulin secretion, insulin action, or both.
Cause of T1D?
- Unclear
- There may be a genetic component, but it is not inherited in any clear pattern.
- Certain viruses, such as the Coxsackie B and enterovirus, may trigger it.
What is the classic triad of symptoms of hyperglycaemia?
1) Polyuria (excess urine)
2) Polydipsia (excess thirst)
3) Weight loss (mainly through dehydration)
In patients with undiagnosed T1D, how may they typically present?
In diabetic ketoacidosis (DKA)
How can the risk of complications of T1D be reduced?
By keeping circulating glucose levels to as near to normal as possible.
Patients with T1D may present with hypoglycaemia, hyperglycaemia, or DKA.
Give some symptoms of hypoglycaemia
- Tremor
- Sweating
- Dizziness
- Pallor
- Reduced consciousness, coma and death if severe
Management of moderate hypoglycaemia?
Rapid acting glucose (e.g. lucozade) + slower acting glucose (e.g. biscuits and toast)
2 management options for severe hypoglycaemia?
1) IV dextrose
2) IM glucagon
What is ketogenesis? When does it occur?
What - production of ketones, liver takes fatty acids and converts them to ketones
When - insufficient glucose supply and glycogen stores are exhausted e.g. prolonged fasting
What are ketones?
Ketones are water-soluble fatty acids that can be used as fuel.
Can ketones cross the BBB?
Yes - and can be used by the brain
How are ketone levels measured?
Urine –> dipstick test
Blood –> ketone meter
What is characteristic breath smell of people in ketosis?
Acetone smell to breath
How do ketones affect blood pH?
How is this buffered in healthy people?
Ketones make blood more acidic.
In healthy people, the kidneys buffer ketones so the blood does not become acidotic.