Diabetes Mellitus Flashcards
Describe Diabetes Mellitus
Diabetes Mellitus is a group of metabolic disorders characterised by chronic hyperglycaemia due to insulin deficiency, insulin resistance or both.
Why type of Diabetes Mellitus is more prevalent in young people?
Type I
How can viral infections contribute to the development of Type I Diabetes?
It is thought a viral infection stimulates lymphocytes, macrophages and antibodies which destroy Beta cells
What is the Triad of symptoms related to Type I Diabetes?
Polydipsia
Polyurea
Weight loss
What is Polydipsia?
Excessive thirst and drinking
What is Polyurea?
Excess urine production
Why do Type I Diabetics experience Polyurea?
There is excess Glucose in the blood and this is filtered in the kidneys.
The extra Glucose in the kidney increases the osmotic load so less water is reabsorbed to maintain osmotic pressures.
How can Type I Diabetes be diagnosed?
Increased levels of Glucose in the blood because of a lack of Insulin
What does lack of Insulin cause?
Decreased uptake of Glucose into adipose tissue and skeletal muscle
Decreased storage of Glucose as Glycogen in the liver and muscles
Increased Gluconeogenesis in the liver
What is Glycosuria?
Glucose in the urine
What happens to the level of Beta cells in Type II Diabetics?
They gradually decrease until none are left - develop disorders of Insulin secretion or Insulin resistance
What is the progression of Type I Diabetes?
Found with HLA markers and auto-antibodies
Develop impaired Glucose intolerance
Develop Diabetes
Become Insulin dependent
What is the progression of Type II Diabetes?
Insulin resistance
Insulin production falls
Impaired Glucose tolerance
Diabetes developed - controlled by lifestyle, then drugs, then Insulin
What is the random venous plasma glucose concentration for a Diabetes diagnosis?
11.1 mm/L or more
What is the fasting plasma glucose concentration for a Diabetes diagnosis?
7.0 mm/L or more
What is the Plasma glucose concentration (after an oral Glucose tolerance test) for a Diabetes diagnosis?
11.1 mm/L or more 2 hours after 75g anhydrous glucose
Why are high concentrations of ketone bodies produced in Diabetics?
High rates of Beta oxidation of fats occurs in the liver
Low insulin/anti Insulin ratio
How does Ketoacidosis occur in Diabetics?
The H+ associated with ketone bodies leads to metabolic acidosis
How can you test the control of Diabetes?
Ketones in the urine
What are the symptoms of Ketoacidosis?
Nausea Vomiting Abdominal pain Hyperventilation Dehydration
What is the plasma glucose concentration in Hypoglycaemia?
Below 3 mmol/L
How can a Diabetic patient become Hypoglycaemic?
Insulin/Sulphonylurea treatment with increased activity, missed meals or overdoses
What is the fatal plasma Glucose concentration and why?
Below 2 mmol/L because the CNS and brain cannot function without Glucose
What are the symptoms of Hypoglycaemia?
Sweating Anxiety Tremors Palpatations Seizures Coma
What is the plasma glucose concentration in Hyperglycaemia?
Blood glucose above 10 mmol/L
What are the symptoms of Hyperglycaemia?
Tiredness Blurred vision Polyurea Polydipsia Weight loss
What drugs can be used to treat Type II diabetes?
Sulphonylureas - they increase insulin release from beta cells and reduce insulin resistance
How can persistent Hyperglycaemia result in depleted NADPH?
There is abnormal metabolism of Glucose due to its accumulation in tissues. Sorbitol is produced which damages tissues.
How does non enzymatic glycosylation of plasma proteins occur?
There is high levels of Glucose in the blood and glucose reacts with free amino acid groups to form stable covalent bonds
How does glycosylation of a protein change its function?
It changes the NET charge and 3D structure so function changes
How can glycosylated haemoglobin be used to measure the control of a patient’s condition?
The higher the levels of glycosylated haemoglobin, the worse the control has been over the preceding 2-3 months. A valve above 10% is considered poor.
What are the macrovascular complications of Diabetes?
Increased risk of stroke
Increased risk of MI
Poor circulation to periphery
What are the microvascular complications of Diabetes?
Diabetic eye disease (due to osmotic effects of glucose)
Nephropathy (damage in the Glomerulus)
Diabetic neuropathy (damage to peripheral nerves)
Diabetic feet (gangrene from reduce blood supply)
