Session 10-Diabetes Flashcards
What is diabetes?
When blood glucose is too high and over years leads to damage of small and large blood vessels causing premature death from cardiovascular diseases
True or false: genetics has caused the diabetes epidemic
FALSE - environment
What causes type 1 diabetes mellitus?
Loss of pancreatic beta cells (autoimmune response)
What are the symptoms of type 1 diabetes mellitus?
Polyuria Polydipsia Weight loss Tiredness Acute onset in young patient
Outline the progression of type 1 diabetes from insulin deficiency to possible death
Insulin deficiency -> catabolic state -> hyperglycaemia, ketoacidosis, dehydration -> (if untreated) coma -> death
How does type 1 diabetes lead to ketoacidosis?
Lack of insulin and elevation of glucagon -> rapid lipolysis in adipose tissue -> excessive fatty acids converted to ketone bodies in liver -> ketoacidosis (+ketonuria)
What are the effects of ketoacidosis?
Hyperventilation Nausea Vomiting Abdominal pain Ultimately coma
How does type 1 diabetes lead to hyperglycaemia?
Lack of insulin and elevation of glucagon -> hepatic glycogenolyis increases + hepatic gluconeogenesis increases + peripheral glucose uptake reduced -> hyperglycaemia
What are the effects of hyperglycaemia?
Osmotic diuresis -> glucosuria + polyuria + dehydration (leads to polydipsia and confusion)
What are the tests for type 1 diabetes?
- urine (glucose and ketones)
- finger prick (glucose and ketones)
- smell of acetone on breath
- blood sample for glucose urea, electrolytes HbA1c
- signs of dehydration
- BP, pulse, chest sounds
- resp rate
What are the two major components in the treatment of type 1 diabetes?
- Diet and exercise
- Insulin therapy
Why are oral glucose-lowering drugs generally avoided in type 1 diabetes?
Risk of hypoglycaemia
What are the chronic macrovascular complications of diabetes mellitus?
- increased risk of stroke
- increased risk of MI
- poor circulation to periphery (feet)
What are the microvascular complications of diabetes mellitus?
- diabetic eye disease
- retinopathy: damage to blood vessels in retina -> blindness
- nephropathy: damage to glomeruli -> microalbuminuria
- neuropathy: peripheral nerve damage
- diabetic foot: poor blood supply, damage to nerves, increased risk of infection
What causes type 2 diabetes mellitus?
Insufficient insulin production from beta cells in setting of insulin resistance
What % of type 2 diabetics are obese?
> 85%
True or false: ketoacidosis occurs in type 2 diabetes
FALSE
What is the HbA1c test?
Measure of glycated haemoglobin reflecting average glycaemia over a period of weeks
What is glycosylation?
- Post-translational modification mediated by enzymes
- Defined carb molecule added to pre-determined region of protein
- Carb plays natural role in protein function
What is glycation?
- Random non-enzymatic reaction
- Sugar covalently attached to protein creating unnatural glycated product
- Impairs protein function and stability
True or false: glycosylation is associated with disease processes
FALSE - glycation (eg chronic hyperglycaemia results in glycation of proteins)
What are the three major components in the treatment of type 2 diabetes?
- diet and exercise
- oral hypoglycaemic therapy
- insulin therapy
How does metformin treat type 2 diabetes?
Reduces hepatic glucose output by inhibiting gluconeogenesis
How does sulphonylurea treat type 2 diabetes?
Modulates ATP sensitive K+ channel function by decreasing open probability and stimulates insulin secretion
