Diabetes Flashcards
1
Q
What are the symptoms of diabetes?
A
- Polyuria
- Blurring of vision
- Thirst
- Weight load
In its most severe forms the following may develop: - Ketoacidosis
- Hypersmolar hyperglycaemia state (HHS)
2
Q
How to diagnose diabetes?
A
A blood test will be taken to assess the blood glucose levels
If you have diabetes:
Fasting plasma glucose = Greater then or equal to 7.0 mmol/L
2hr plasma glucose = Greater then or equal to 11.1 mmol/L
If you have ore diabetes:
Fasting plasma glucose = Less then 7.0mmol/L
2 hr plasma glucose = Greater then or equal to 7.8 mmol/L and less the 11.1 mmol/L
3
Q
What is type one diabetes?
A
- THe development of hyperglycaemia in type 1 diabetes results from the failure of the B- cells of the pancreas to produce insulin in the presence of:
- islet cell antibodies
- Insulin antibodies
- Antibodies to glutamic acid decarboxylase
It is a slow onset auto immune disease
The destruction of the pancreatic islet B- cells leads to the development of type 1 diabetes
4
Q
What is gestational diabetes (GDM)?
A
- GDM results due to the disturbances of the carbohydrate metabolism which leads to hyperglycaemia and is detected during pregnancy
- Diabetes mellitus which is discovered in pregnancy is not classified as GDM instead the woman is seen as having diabetes myelitis and pregnancy
- The profound hormonal changes which take place during pregnancy, dealing beta cell function and insulin resistance may lead to hyperglycaemia and manifestation of GDM
5
Q
What are the risks of GDM?
A
- There is evidence that hyperglycaemia detected in pregnancy is a risk factor for adverse pregnancy outcomes. E.g large for gestational age and pre-eclampsia
- Individuals with GDM are also at risk of developing type 2 diabetes in the future. Their children are also at risk of developing childhood obesity and type 2 diabetes later on in life
6
Q
What is type 2 diabetes?
A
- This is where there is an insufficient amount of insulin production
- Hyperglycaemia can also result form the failure of insulin to exert its biological influence of the level in the liver and the muscle in order to facilitate the diffusion of glucose into the cells to be used for energy, stores as glycogen or fat
- A combination of lack of insulin secretion resulting in B-cell dysfunction and/ or insulin resistance can lead to glucose disregulation and hyperglycaemia.
- The actions of counter regulatory hormones such as adrenaline, cortisol, and glucagon in counteracting the action of insulin in diabetes are also crucial in the pathophysiology of type 2 diabetes
7
Q
What are some of the risk factors for type 2 diabetes?
A
- Genetic (family history)
- Environmental factors ( Diet, physical activity)
- Obesity ( release of NEFAs from fat cells)
- Body fat distribution ( central fat is related to insulin- Persistent in south Asian population.
- Age
- Ethnicity ( SE Asia and Afro Caribbean)
- Certain syndromes (e.g downs and turners)
- Pregnancy
- Smoking
- Drugs such as steroids
- Stress
8
Q
What us the mechanism of insulin action?
A
- Insulin locked onto the insulin receptor in the cell membrane
- Causing a chemical reaction in the cytoplasm
- Leading to a translocation of a glucose transporter (GLUT4) from the cytoplasm to the cell membrane
- Because there us a higher concentration of glucose molecules outside the cell diffusion occurs. In order for diffusion to happen it needs to be supported by the glucose transporter (GLUT4)
- Excess glucose is stored as Glycogen (the body can then break this down when needed to make glucose ie when the body’s blood sugar levels are low)
9
Q
How does the body break down glycogen?
A
- To break down glycogen
- The body has to produce glucagon
- Once the glucagon has broken down the glycogen, glucose is formed and can be used to produce energy and increase blood sugar levels
10
Q
Homeostatic role of insulin and glucagon for low blood sugar
A
- Low blood glucose
- Pancreas
- Glucagon released by alpha cells of pancreas
- liver releases glucose into the blood
- Achieve normal blood glucose levels
11
Q
Homeostatic role of insulin and glucagon for high blood sugar
A
- High blood glucose
- Pancreas
- Insulin released by beta cells of the pancreas
- Fat cells take in glucose from blood
- Achieve normal blood glucose levels
12
Q
What are the metabolic effects of insulin deficiency?
A
- Accelerated glycogenolysis (breakdown of glycogen)
- Increased glycogenesis (synthesis of glucose from non- carbohydrate sources)
- Decreased entrance of glucose into peripheral tissues
- Hyper glycaemia
- Glycosuria
- Accelerated oxidation of fatty acid in the liver
13
Q
What is Glucagon?
A
- A hyperglycaemic pancreatic hormone
- Promotes increase in blood glucose concentration
- It’s action is opposed to that of insulin
- Promotes breakdown of liver glycogen
- Inhibits the breakdown of the glucose to lactate by glycolysis
14
Q
Type 2 diabetes can result from …
A
- Insulin deficiency resulting from B- cells dysfunction
- The body’s resistance to the action of insulin’s the liver and peripheral tissues being the sites of insulin resistance
- A combination of both insulin resistance and insulin deficiency
- Hepatic glucose production via glycogenolysis and gluconeogenisis increases blood glucose levels
15
Q
Explain the B- cell dysfunction in type 2 diabetes
A
- Hyperglycaemia may result from the failure of the B cells to compensate for defects in insulin action this, leading to type 2 diabetes
- Impaired B cells function may be due to the loss of B cell mass following amyloid (islet polypeptide) deposits and for glucose toxicity
