Diabetes Flashcards
Describe the normal profile of plasma insulin throughout the day
Peaks at mealtimes with basal levels inbetween
In a normal person, what triggers an increase in insulin?
- increased glucose
- incretins (GLP-1, GIP)
- glucagon
- parasympathetic activity (M3)
In a normal person, what triggers a decrease in insulin?
- decreased glucose
- cortisol
- sympathetic activity (alpha 2)
What is the role of insulin?
- Decreased hepatic glucose output by inhibiting gluconeogenesis
- Inhibits glycogenolysis
- Promotes uptake of fats
What level of glucose in a random plasma glucose test would suggest diabetes?
plasma glucose _>_11 mmol/L
What are some of the symptoms of diabetes?
- polyuria
- polydipsia
- weight loss
- fatigue/ lethargy
What are some risk factors for developing type 2 diabetes?
- Obesity - 80/85% risk
- Family history
- Ethnicity
- Poor diet
- Drugs - thiazide/ thiazide like diuretics, glucocorticoids, Beta blockers
- Low birth weight (some evidence)
What 2 blood measurements are usually taken when monitoring diabetics?
- Blood glucose - immediate measure of glucose
- HbA1c- glycated Hb, reflets the average blood sugar over last 10-12 weeks
Why must insulin be given parenterally?
Insulin is a protein so would be digested in the gut if given orally
What form of insulin is given to patients in the UK today?
Recombinant form of human insulin (bacteria/ yeast)
or, enzymatic modification of porcine
What is the usual formulation of insulin given?
100 U/ mL
(although 300 and 500 U/mL are available)
How do you administer insulin?
- Routinely delivered by subcutaneus injection
- To; upper arms, thighs, buttocks, abdomen
- Can be given intravenously for emergency treatment
When is concentration of insulin in plasma highest after meals?
When would you administer insulin around meal times?
Greatest 2-3 hours post meals
Administer 15-30 mins prior to meals
Why must you change the site of administration of insulin injections?
Repeated injection at the same site can cause lipdystrophy
(atrophy/ hypertrophy of lipid profile around the site changes absorption)
What are the different preparations of insulin?
(onset of action, peak of action, duration, class)
In which patients would you avoid giving insulin to?
- Hypoglycaemic patients
- Lipohypertrophic patients
- Lipoatrophic patients
- Patients with renal impairment
All have a risk of hypoglycaemia
In which patients do you have to use insulin with caution?
- increased doses on patients with steroids
- use with caution if on other hypoglycaemic agents
What is the benefit of delivering insulin via a pump?
- reduces long term cost
- less errors in dosing
- less change of hypoglycaemia
What is basal bolus dosing for insulin?
A bolus dose is given around mealtimes- rapid acting e.g. aspart
A long acting (basal) dose is given to maintain basal levels - long acting e.g. glargine
When would you suspect diabetic ketoacidosis?
Blood glucose >11 mmol/L AND
- infection
- stress/ trauma
- poor insulin adherance
- adverse drug reaction
- ketosis
What is the primary treatment for treating diabetic ketoacidosis?
Fluids are the priority, followed by insulin
What is the secondary treatment for DKA
After fluids and insulin give…
Glucose and potassium
Why do you need to give potassium in DKA?
Due to acidosis there is reciprocal movement of H+(into cells) and K+ (out of cells)
K+ movement out of cells causes eventual loss that will need to be replaced
Always monitor with an ECG due to changes in potassium
What pathological changes happen in type 2 diabetes?
- A reduction in sensitivity to insulin into cells
- Insulin resistance initally overcome by an increase in pancreatic insulin secretion
- Eventual decrease in insulin receptors and decrease in GLP-1 secretion
- Glucotoxicity from fatty acids and ROS can cause Beta cell dysfunction
