An overview of diabetes Flashcards
What is the greek original word for Diabetes?
Siphon
What is the greek original word for Mellitus?
Honey
What is diabetes?
Group of metabolic disorders characterised by hyperglycemia
What are the symptoms of diabetes?
Polyuria
Polydypsia
Unexplained weight loss
Are all patients symptomatic?
No
What causes type I diabetes?
Immune mediated
Idiopathic
What percentage of the diabetic population has Type II diabetes?
85%
What are possible causes of type I diabetes?
Viral cause
Genetic predisposition
What is gestational diabetes?
Diabetes diagnosed in pregnancy
Does everyone with diabetes present with symptoms?
No
What are the diagnostic criteria for patients with diabetes symptoms?
A random venous plasma glucose concentration above 11.1 mmol/l
A fasting plasma glucose concentration above 7 mmol/l
A two hour plasma glucose concentration above 11.1 mmol/l two hours after 75g anhydrous glucose in an oral glucose tolerance test
What are the diagnostic criteria for patients without diabetes symptoms?
Diagnosis should depend on the outcome of more than one plasma glucose determination test
Test should be taken on separate days
If the fasting values are not diagnostic, the two hour value should be used
How is HbA1c used for diabetes diagnosis?
It is used to identify the 3-month average plasma glucose concentration
Provides more than just a snapshot of the blood glucose levels
How is the HbA1c concentration related to the blood glucose?
The higher the HbA1c concentration, the higher the blood glucose concentration has been over 3 months
Why does HbA1c reflect the blood glucose levels over a 3 month period?
Once a haemoglobin molecule is glycated, it remains that way
A buildup of glycated haemoglobin within the red cell reflect the average level of glucose to which the cell has been exposed to during its life cycle
In which situations is HbA1c not appropriate for diabetes diagnosis?
All children and young people
Patients of any age suspected of having type I diabetes
Patients with symptoms of diabetes less than 2 months
Patients at risk who are actually ill
Patients taking medication that may cause rapid glucose rise
Patients with acute pancreatic damage
Pregnancy
Presence of genetic, haematologic and illness-related factors that influence HbA1c and its measurement
Which cells produce insulin?
Beta cells of the pancreas
What causes insulin to be released?
Increased blood glucose
What is the major function of insulin?
Maintains low blood glucose
What are the other functions of insulin?
Stimulates lipogenesis
Decreases lipolysis
Increases amino acid and glucose transport into cells
Increases glycogen synthesis
Describe the steps of insulin release and delivery to tissues
- Beta cells are clustered together into islets in the pancreas
- When glucose is released from capillaries into the pancreatic tissue, it triggers the release of insulin from beta cells
- Insulin travels to other parts of the body, mainly muscle and fat
- Here, insulin helps store glucose for energy
- The surfaces of muscle and fat are covered in insulin receptors
- When insulin binds to the insulin receptor, it brings the extracellular structures of the receptor together and causes the intracellular structures to unwind
- The intracellular protein sets off a long signalling cascade
- The cascade causes the intracellular receptor glut4 to translocate into the cellular membrane
- This allows glucose into the cells.
What is lacking in type I diabetes?
Insulin
Beta cells get destroyed
What is lacking in type II diabetes?
Insulin receptor sensitivity
What is the main risk factor for type II diabetes?
Obesity
