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Flashcards in Insulin Therapy Deck (15)
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What's the final structure of insulin in secretory vesicles?

Hexamers with zinc.


Review: 3 ways to stimulate insulin?

Glucose in blood.
Autonomic nerves - seeing, smelling food.
Hormonal - incretins from gut.


How is endogenous insulin metabolized? How does this compare with exogenous insulin?

Endogenous: much goes in portal vein to liver -> 60% hepatic, 40% renal.
Exogenous: Mostly renal.


What's the typical concentration of injected insulin? Why would you want something more potent?

Typical concentration = 100 units / ml (U-100).
U-500 R is used when people are very insulin resistant.


What are the 3 "speeds" of insulin preparations? Examples of each?

Rapid-acting: human analogues (Aspart, Lispro)
Short-acting: crystalline zinc (regular human insulin)
Long-acting: glargine, NPH + protamine


What chemical properties make rapid-acting insulin different from short-acting insulin?
What's the difference in speed of onset?

Rapid-acting has changes that disrupt monomer-monomer interactions - so more insulin is in the active form right away.
Rapid: 5-15 min.
Short-acting: 30-60 min.


Do non-diabetic persons only produce insulin after meals?

Nope, there's a basal insulin secretion throughout the day. - which long-acting insulins try to mimic.


What is NPH? Duration of action?

Neutral protamine hagedorn: crystalline insulin with zinc + a positively charged peptide, protamine.
Has activity for 10-20 hours.
(Insert joke about How I Met Your Mother)


Why is glargine long-acting?

With its acidic pH, it precipitates, and takes a long time to be absorbed after being given SubQ.


Why is detemir long acting?

It's acylated with myristic acid... so it binds albumin. Slow release keeps insulin at a basal level for a long time (up to 24hrs).


Which insulins have no "peak"?

Glargine and detemir, which is desirable.


When do you use IV insulin?

Emergencies in the hospital - e.g. DKA.


What are 3 common insulin regimens? Which ones are more preferred?

NPH + Lispro (rapid-acting) fixed doses at breakfast and dinner. (not preferred, but simpler)
Lispro pump providing basal infusion and meal-time boluses (preferred).
"Basal-bolus" -once daily glargine + carb-calculated Lispro at mealtimes (preferred).


5 factors affecting the appropriate insulin dose to give?

Blood glucose
Carbs consumed
Insulin sensitivity
Physical activity (must give less insulin when exercise)


4 complications of insulin therapy?

Lipodystrophy (can be atrophy or hypertrophy)
Insulin resistance (can be Ab-mediated)