Background of diabetes Flashcards
Type 1 Diabetes pathophysiology + presentation?
Autoimmune disorder where the insulin-producing beta cells of the islets of Langerhans in the pancreas are destroyed by the immune system
This results in an absolute deficiency of insulin resulting in raised glucose levels
Tends to develop in childhood/early adult life and typically present unwell, possibly in diabetic ketoacidosis
Type 2 diabetes pathophysiology?
Most common cause of diabetes in the developed world
caused by a relative deficiency of insulin due to an excess of adipose tissue
In simple terms there isn’t enough insulin to ‘go around’ all the excess fatty tissue, leading to blood glucose creeping up.
Prediabetes term used for?
patients who don’t yet meet the criteria for a formal diagnosis of T2DM to be made but are likely to develop the condition over the next few years. They, therefore, require closer monitoring and lifestyle interventions such as weight loss
Gestational diabetes?
Some pregnant develop raised glucose levels during pregnancy. This is important to detect as untreated it may lead to adverse outcomes for the mother and baby
Maturity onset diabetes of the young (MODY)?
A group of inherited genetic disorders affecting the production of insulin. Results in younger patients developing symptoms similar to those with T2DM, i.e. asymptomatic hyperglycaemia with progression to more severe complications such as diabetic ketoacidosis
Latent autoimmune diabetes of adults (LADA)
The majority of patients with autoimmune-related diabetes present younger in life. There are however a small group of patients who develop such problems later in life. These patients are often misdiagnosed as having T2DM
Other types of diabetes?
Any pathological process which damages the insulin-producing cells of the pancreas may cause diabetes to develop. Examples include chronic pancreatitis and haemochromatosis.
Drugs may also cause raised glucose levels. A common example is glucocorticoids which commonly result in raised blood glucose levels
Symptoms and signs of Type 1
Weight loss
Polydipsia
Polyuria
May present with diabetic ketoacidosis
- abdominal pain
- vomiting
- reduced consciousness level
Signs and symptoms Type 2
Often picked up incidentally on routine blood tests
Polydipsia
Polyuria
What are polydipsia and polyuria due to?
water being ‘dragged’ out of the body due to the osmotic effects of excess blood glucose being excreted in the urine (glycosuria).
What are the 4 main ways to check blood glucose?
a finger-prick bedside glucose monitor
a one-off blood glucose. This may either be fasting or non-fasting
a HbA1c. This measures the amount of glycosylated haemoglobin and represents the average blood glucose over the past 2-3 months
a glucose tolerance test. In this test, a fasting blood glucose is taken after which a 75g glucose load is taken. After 2 hours a second blood glucose reading is then taken
The diagnostic criteria: if a patient is symptomatic?
fasting glucose greater than or equal to 7.0 mmol/l
random glucose greater than or equal to 11.1 mmol/l (or after 75g oral glucose tolerance test)
The diagnostic criteria: if the patient is asymptomatic?
fasting glucose greater than or equal to 7.0 mmol/l
random glucose greater than or equal to 11.1 mmol/l (or after 75g oral glucose tolerance test)
MUST be demonstrated on TWO separate occasions
supplementary guidance on the use of HbA1c for the diagnosis of diabetes:
a HbA1c of greater than or equal to 6.5% (48 mmol/mol) is diagnostic of diabetes mellitus
a HbAlc value of less than 6.5% does not exclude diabetes (i.e. it is not as sensitive as fasting samples for detecting diabetes)
in patients without symptoms, the test must be repeated to confirm the diagnosis
it should be remembered that misleading HbA1c results can be caused by increased red cell turnover
Type 1 diabetes general management
patients always require insulin to control the blood sugar levels. This is because there is an absolute deficiency of insulin with no pancreatic tissue left to stimulate with drugs
different types of insulin are available according to their duration of action
