Session 5: Diabetes Flashcards
What stimulates insulin secretion?
Increase in glucose
Incretins like GLP-1 and GIP
Glucagon
Parasympathetic activity via M3
What is insulin inhibited by?
Decrease in glucose
Cortisol
Sympathetic activity (alpha 2)
Role of insulin
Reduce hepatic glucose output via inhibition of gluconeogenesis
Inhibits glycogenolysis
Promotes uptake of fats
Diagnostic criteria of diabetes.
Hyperglycaemia with a random plasma glucose >11 mmol/l
Some symptoms such as polyuria, polydipsia, weight loss, fatigue/lethargy.
Single raised plasma glucose without symptoms is not sufficient.
Risk factors of type 2 diabetes.
Obesity
FH
Ethnicity
Diet
Drugs like thiazides, glucocorticoids and b-blockers
Low birth weight
Ways to investigate diabetes.
Glucose levels in blood
HbA1c levels (glycated haemoglobin) which reflects the average blood sugar over last 10-12 weeks.
What is insulin made from?
Human insulin via recombinant DNA and reproduced via bacteria or yeast.
Or
Enzymatic modification of porcine insulin.
How is insulin given and why?
Parenterally to avoid digestion in the gut.
This is because it is a protein.
Routine administration of insulin.
Subcutaneous injection in upper arms, thighs, buttocks or/and abdomen.
IV is only given for emergencies.
Pharmacokinetics of insulin.
Half-life of 5 minutes in plasma and both renal and hepatic metabolism as well as elimination.
When should insulin be given?
15-30 min prior to a meal.
Why might protamine and/or zinc be given in the same dose as insulin?
To modify absorption.
What are insulin analogues and why might they be given?
A lab-grown modification of insulin to make it for example more rapidly acting.
Why is it important to rotate the site of administration of insulin?
Because given in the same spot can lead to lipodystrophy.
What are insulin aspart and insulin glargine?
Insulin analogues
What is Ispophane/NPH insulin?
Insulin mixed with protamine and zinc.
This gives a slower acting insulin
Are combinations of insulin prescribed?
Yes.
Short and long acting mixtures of insulin can be prescribed and they may be taken separately.
How might insulin be administered? (what equipment)
By syringes, pens, pumps or inhalers
ADRs of insulin
Hypoglycaemia
Lipohypertrophy
Lipoatrophy
Also renal impairment leads to a higher risk of hypoglycaemia.
When should you not take/be careful insulin?
When with steroids
Other hypoglycaemic agents
Give an example of a bolus dosing insulin.
Insulin Aspart which is rapid acting
Give an example of a basal dosing insulin.
A long acting such as Insulin glargine
What is diabetic ketoacidosis?
Hyperglycaemia
Acidosis
Ketonaemia
When should you suspect DKA?
When blood glucose is above 11 mmol/l and there is:
an infection
Stress or trauma
Poor insulin adherence
ADRs
ketosis
Hyperglycaemi may not always be present and it can also present with low blood ketones.
Treatment of DKA
Prioritise fluids due to huge diuresis and then you give insulin.
You may also give glucose and K+ in order to not make them go hypoglycaemic or hypokalaemic.
How is the insulin resistance usually overcome in T2DM?
By increased pancreatic insulin secretion.
What will the increase in pancreatic insulin secretion lead to?
Decrease in expression of insulin receptors and therefore less GLP-1 secretion in response to oral glucose as well.
How does beta-cell dysfunction happen in T2DM?
Glucotoxicity from fatty acids and ROS will cause beta-cell dysfunction.
What are the initial treatments of T2DM?
Lifestyle modifications
Education
Surgery
Why might adherence be low when been given insulin?
Due to perceived hypoglycaemia and perceived weight gain.