Diabetes Mellitus Flashcards
What is Diabetes Mellitus
What are the criteria for diagnosis
A group of metabolic diseases characterised by Chronic Hyperglycaemia and Elevated glucose in urine
- Symptoms
- Random plasma [glucose]> 11.1 mmol/L
OR
Fasting plasma [glucose]> 7.0 mmol/L
OR
2h after glucose in Oral Glucose Tolerance Test> 11.1 mmol/L
Differ between Absolute and Relative Insulin Deficiency
Absolute: Beta cells destroyed
Relative: Abnormally slow/ small secretory response of Beta cells
If a patient is symptomatic, how many tests must be abnormal for a diabetes diagnosis?
What if patient is asymptomatic
Symptomatic: 1 abnormal test
Asymptomatic: 2 abnormal tests
What is Type 1 Diabetes
It is caused by a mix of genetic and environmental factors, what 2 genetic markers are associated?
Absolute insulin deficiency due to autoimmune destruction of Beta cells
HLA DR3 and HLA DR4
What are 2 mechanisms of Type 2 Diabetes
Relative insulin deficiency
Insulin resistance
How does insulin resistance onset before 12 years, lead to type 2 diabetes
Initially;
- Beta cells increase insulin production to maintain normal blood glucose
Eventually;
- Beta cells unable to maintain increased insulin production
Finally;
- Beta cell dysfunction-> Relative insulin deficiency
What are the 2 groups of symptoms of Diabetes Mellitus?
Give 3 examples of each
Symptoms due to hyperglycaemia;
- Polyuria (Excess urine)
- Polydipsia (Thirst)
- Blurred vision
Symptoms due to inadequate energy utilisation;
- Tiredness
- Weakness
- Weight loss
Name 4 symptoms of Type 1 Diabetes
In late stage, what may be detected in urine?
What does this mean?
- Weight loss
- Polyuria
- Polydipsia
- If late presentation, vomiting due to Ketoacidosis (Fatal)
- Ketones in urine, means lack of insulin
How is Type 1 diabetes treated?
If ketones are seen in urine, what do you do?
Exogenous insulin injected subcutaneously several times a day for life
Immediate insulin therapy
What are 3 characteristics of Ketoacidosis
Hyperglycaemia
Ketonaemia
Acidosis
What is Type 2 Diabetes
Long-term metabolic disorder characterised by Hyperglycaemia, insulin resistance, and relative insulin deficiency
Name 5 causes of insulin resistance
- Obesity
- Fat deposition in muscle and liver
- Physical inactivity
- Genetics
- Elevated circulating free fatty acids
Are Type 2 Diabtes patients symptomatic?
Compare the rise in blood glucose to that of Type 1?
Name 2 drugs used to manage Type 2 diabetes, describe how they work
- May be asymptomatic
- Type 2: Slower rise in blood glucose than in Type 1
- Sulphonylureas: Reduce insulin resistance and increase insulin release from remaining Beta cells
- Metformin: Reduces gluconeogenesis
If symptomatic, name the symptoms of Type 2 Diabetics
Can ketones be found in urine?
- May have Polyuria, Polydipsia, weight loss (Classical triad)
- No ketones in urine
Other than Sulphonylureas and Metformin, suggest 2 management techniques for Type 2 Diabetes
- Lifestyle changes
- Insulin
Describe 3 metabolic consequences of Persistent Hyperglycaemia
- Increased [Glucose} in cells;
- NADPH depleted to make Sorbitol
- Disulphide bonds-> Altered cell structure/ function
- Sorbitol causes osmotic damage - Increased glycation (Non-enzymatic glycosylation) of plasma proteins;
- Altered function - Formation of Glycated Hb (HbA1c)
How much Hb is Glycated (HbA1c) in;
- Normal healthy people
- Poorly controlled diabetics
Normal: 4-6%
Poorly controlled Diabetics: 10% or more
Identify 1 ACUTE complication each of Hyperglycaemia and Hypoglycaemia due to Diabetes
- Hyperglycaemia- Massive metabolic decompensation
- Diabetic Ketoacidosis in Type 1
- Hyperosmolar non-ketotic Syndrome in Type 2
- Hypoglycaemia- Coma due to hypoglycaemic therapy
What are 2 groups of chronic complications of Diabetes?
Give 3 examples and 5 examples
- Macrovascular disease;
- Stroke
- Myocardial Infarction
- Poor circulation to periphery - Microvascular disease;
- Diabetic eye disease (Lens change due to glucose’s osmotic effects)
- Retinopathy (Damaged blood vessels in retina-> Blindness)
- Nephropathy (Poor blood supply damages glomerulus)
- Neuropathy (Peripheral nerve damage-> Sensation loss)
- Diabetic feet (Poor blood supply, nerve damage, ulcers, increased infection risk)
What is Metabolic Syndrome
A cluster of the most dangerous risk factors associated with Cardiovascular Disease;
- Diabetes + Raised fasting plasma glucose
- Abdominal/ Central obesity
- High cholesterol
- High Blood Pressure
List 5 causes of Metabolic Syndrome
- Insulin resistance
- Central/ abdominal obesity
- Genetics
- Physical inactivity
- Ageing
What are the 5 criteria for having Metabolic Syndrome
- Waist measurement (> 94cm men/ >80 cm women)
Plus any 2 of;
- Raised triglyceride
- Reduced HDL
- Raised BP
- Raised fasting blood glucose
What does Aetiology mean?
What are the 2 most important factors underlying the aetiology of Metabolic Syndrome?
Underlying cause of a disease
Insulin resistance
Central obesity
Which change in DNA makes you more susceptible to Diabetes, Obesity and Cardiovascular disease in adult life?
DNA Methylation
