L17 - Diabetes Flashcards
Where is insulin produced and what roles does it have?
- produced in the pancreas
roles:
- transport glucose from blood supply into fat and muscle cells where it can be used for energy
- stops liver gluconeogenesis once the level of glucose in the blood is high enough
What is the effect of diet on blood glucose?
- high sugar foods cause short but high increase in glucose levels
- fibre in the diet slows absorption so high fibre diet slows the spike in glucose
- low GI (glycaemic index) foods have a gradual increase in blood glucose over a longer time
What are the effects of lack of insulin?
- low cellular glucose intake
- reduced fuel = metabolic issues = tired because insufficient energy
- high blood glucose - can damage vessels and increase risk of cardiovascular disease
How does insulin work?
- secreted into portal (liver) circulation
- insulin binds to transporter
- increased GLUT4 synthesis
- transports glucose into the cell
What are the types of diabetes?
type I - insulin dependent diabetes - due to too little insulin - pancreas not producing enough - genetic factor type 2: - insulin independent - cellular desensitisation to insulin - environmental influence
others:
secondary diabetes due to damage to the pancreas
gestational diabetes
What is the treatment for type 1 diabetes?
replace the insulin
- patient must take daily injections of insulin to survive
Why does insulin need to be injected?
because insulin has a bioavailability of 0% - it gets broken down by the stomach acid and emzymes in the GIT
What is the difference between intravenous and subcutaneous administration of insulin in type 1 diabetes?
- IV usually only used in emergency situation (first discover diabetic)
- subcutaneous reaches a lower peak but it is longer. less painful injections and easier to self administer
How do diabetics know they need insulin?
use a Glucometer (glucose meter)
recommendations: 5.0-7.2 mmol/L before meals, less than 10 mmol/L after meals
What are the best sites to inject insulin?
fast absorption areas = arms + abdomen because large blood flow slowed by abdominal fat
slowest absorption areas = thighs and buttocks due to fat (increased absorption by exercise)
need to change sites regularly otherwise can develop hard lumps which reduce absorption
What are the types of insulin for type 1 diabetes?
rapid acting (Novo Rapid)
- acts immediately
- but short duration (1-2 hours)
- used straight before or after a meal
- for random adjustments throughout the day
short acting (Actrapid)
- acts after 30 minutes
- lasts up to 4 hours
- used for main meals of the day
intermediate/long acting (Humulin NPH, protaphane)
- acts after an hour
- lasts all day
- used for patients with strict lifestyle and diet who dont want to use medication all day
- used for once or twice daily dosing
What are the factors affecting selection of ideal insulin protocol?
- patient understanding of need for insulin
- patient willingness to self-inject
- patient fear of diabetic complications
- patient preference for some dietary flexibility
What is treatment plan 1: minimum choice protocol?
- patient wants minimal participation in decision making
- patient prefers set diet and exercise schedules with set meal and snack times (meals with low GI foods + little/no snacking)
- usually prefers insulin protocol with little flexibility
- good stability without hypos
- because of inflexibility, “cheating” cannot be compensated
What is treatment plan 2: tight protocol?
- patient wants to maintain optimal blood glucose levels at all times
- wants to be proactive and self-managing
- 2 part protocol: maintain basal insulin level + add meal/snack insulin as required
- patient continuously monitors and adjusts own requirements
- greater probability of hypoglycaemia
What factors is type 2 diabetes associated with?
- obesity
- lack of exercise
- poor diet
