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
How many people in the UK have been diagnosed with diabetes?
3.7 million
The diabetic population in the UK has doubled in the last 20 years
TRUE or FALSE
TRUE
What percentage of people with diabetes are overweight?
80%
What is the underlying pathogenic mechanism behind type II diabetes?
Insulin resistance
B-cell dysfunction
What happens early on the disease progression in type II diabetes?
Pancreatic b-cells compensate for the insulin resistance by producing increased amounts of insulin
When insulin resistance increases past a threshold level, the body can no longer compensate
This results in hyperglycemia
What are non-modifiable risk factors of diabetes?
Age
Family history
Ethnicity
History of gestational diabetes
Polycystic ovarian syndrome 1
What are modifiable risk factors of diabetes?
Overweight and obesity
Physical inactivity
Disturbances in intraurine development
Metabolic syndrome
Dietary factors
Depression
Low socio-economic status
Which pathways link obesity to insulin resistance?
Endocrine, inflammatory and neuronal pathways
Which physiological changes in obesity inhibit insulin signaling?
Obesity-associated inflammatory factors
Endocrine and inflammatory mediators converging on kinases
Increasing fatty acid concentration
How have GWAS been helpful in Type 2 diabetes?
Helped to associate SNPs with Type II diabetes
In which process were the SNPs associated with type II diabetes involved with?
Pancreatic beta-cell function
Do patients with molecular disorders similar to those that happen in diabetes necessarily express the condition?
No
What type of disorder is type I diabetes considered as?
Autoimmune disorder
Which risk factors have been associated with type I diabetes?
Variants in HLA genes
Accounts for 40% of the genetic risk factor for the condition
What are other types of diabetes?
Maturity onset diabetes
Gestational diabetes
What percentage of the NHS budget is allocated towards diabetes control?
10%
