Type 2 diabetes - 141 Flashcards
Describe diabetes
A disorder of carbohydrate metabolism in which sugars in the body are not oxidised to produce energy due to a lack of (or resistance to) insulin.
This leads to hyperglycaemia
Name some common signs and symptoms of diabetes
Thirst, weight loss, polyuria.
Other symptoms include blurred vision
How is type 2 diabetes different to type 1?
In type 2 the pancreas retains some ability to produce insulin, however the body becomes resistant to its effect
How is diabetes diagnosed?
Resting plasma glucose -> 11.1mmol/l
Fasting plasma glucose -> 7mmol/l
Oral glucose tolerance test -> 75gm oral load after 10hr fast
HbA1c
** Diabetes diagnosed by either venous glucose OR HbA1c levels
Name some pros and cons for using glucose levels as a diagnostic tool for diabetes
Pros: Diabetes is a glucose disease, large amount of data, international comparison, cheap, accurate
Cons: Patient needs to fast, patient cannot smoke, pre-analytical problems.
Name some pros and cons of using HbA1c as a diagnostic tool for diabetes
Pros: No fasting, stable, time averaged,
Cons: Influenced by many factors e.g. pregnancy, anaemia, renal failure, blood transfusion
Describe the process of insulin production
Preproinsulin -> proinsulin -> insulin + C-peptide
How does the 1st phase insulin response differ to the 2nd phase insulin response?
The 1st phase response is rapid and consists of pre-made insulin. This is followed by the 2nd phase which is slower but lasts much longer than the 1st phase.
In type 2 diabetes which phase of insulin release is lost?
The 1st phase -> as the diabetes progresses the patient also loses the 2nd phase
What is GLP-1?
An incretin
What does GLP-1 do?
It is secreted from gut cells in response to increased glucose levels. GLP-1 binds itself to beta cell which increases insulin release and decreases glucagon release. The increased insulin transports glucose to the liver to be stored
Do patients with T2 diabetes have increased or decreased incretins?
Decreased - not enough insulin is produced and too much glucagon is produced
When there is not enough glucose present for an energy source what happens?
The body uses ketone bodies for energy. This can disturbance the acid/base balance and result in ketosis, eventually resulting in a diabetic coma
What a patient with impaired glucose tolerance’s glucose and insulin levels be?
Both will be raised
What is the role of GLUT4?
It transports glucose into tissues.
