Basal and Bolus Insulin [in nature?]

[Member496333]

Hi-de-Hi, campers.

Quick question that I’ve been curious about recently. I could Google it of course but here seems as good a place as any to invite discussion. Basal and bolus insulin. I understand completely the role of each in the context of exogenous (injected) insulin, but are there two types of endogenous (natural) insulin, or does the pancreas only secrete one type regardless of prevailing conditions? In essence my question is; is my pancreas secreting the exact same insulin when I’m fasting as when I’m eating? Or framed another way; is basal and bolus only a thing in exogenous pharmaceutical insulin? My assumption is that there’s only one natural variety, and of course that it’s just released in granular amounts depending on the requirements.

Hope my question is clear. Thanks for reading.

 

[Deleted Account]

My understanding is a natural pancreas only secrets one type of insulin.
The insulin pump mimics this.

Injected basal insulins are "long acting" and assume the body's insulin requirements are constant throughout the day, However, there are times when more or less are needed such as first thing in the morning (dawn phenomenon), when stressed, when exercising.

 

[Member496333]

Thanks. Pretty much as I thought then. I guess I was just curious as to how they manage to make slow and fast acting insulin. The wonders of medical science, I guess.

 

[kitedoc]

Hi @Jim Lahey, without going into the intricate detail (which I am not skilled to do anyway), insulin in its manufacture can have various agents added to either speed up or slow down absorption from the usual injected site under the skin.
The injected insulin is in a depot pool under the skin from where it is taken up into blood vessels.
Early preparations had zinc and protein added to slow up absorption but the absorption was a bit haphazard.
Later on configuration of insulin into hexagonal ring structures or addition of a common body protein provided more reliably absorbed long -acting insulin.
In the meantime the 'holy grail' of insulin was to produce insulin that was very quickly and reliably absorbed in an attempt to catch the rise of BSL after a meal. No-one has quite succeeded but so called modern diets with high carbs has the potential to cause very rapid BSL rises.
The obvious answer (in your thoughts I am certain) is to reduce and prolong the BSL rise via low carb.
It is far easier to adjust diet than spend untold money on a faster and faster insulins.
But do not tell Big Pharma. They will think we are doing them out of money!! Rather than saving on health costs.

 

[Member496333]

Ahhh thank you. I guess this is why I often see folk talking of cycling their “injection sites”.

 

[kitedoc]

Ahhh thank you. I guess this is why I often see folk talking of cycling their “injection sites”.

Yes, good observation. One or two long-acting injections per day and three short-acting, one before each meal is the common multiple daily injection (MDI) protocol. The joke is to remind them not to drink any water for a time after each injection !! 4 to 5 injections per day in a different area each can be a challenge and tricky to keep track of. If one uses all areas, thighs, arms, buttocks and abdomen it is easier. But the insulin is most quickly absorbed from the insulin injected into tissue under the abdominal skin so this is a favourite spot for injecting short-acting insulin.
Too many injections in the same spot can cause scarring of tissue (dystrophy) or sometimes a pad of fatty tissue (hypertrophy) The former causes irregular under-absorption and the latter irregular, quicker absorption.
Fortunately with a pump 'javelin practice' is reduced to every 2nd or 3rd day (with some having to do daily) but the sites for the infusion devices need to be rotated to avoid irregular absorption problems.