1 injection of 5 units vs 5 injections of 1 unit?

[Skater P]

Something that has been bugging me.

I sometimes jab for a main course, then a little later jab again for pudding, so 2 injections close together rather than a single and I wonder is that different to a single injection of the same number of total units. Basically is 1 injection of 5 units the same as 5 injections of a single unit each?

I can see how multiple injections might make the units be absorbed faster (like how a powder disolves faster than a big single lump) but don't know for sure in this case.

Anyone got any ideas?

(Thread title is just a way to articulate the question BTW I'm not doing each unit individually, that would be silly but may well answer the question.)

 

[Inka]

Assuming you’re not taking massive doses of insulin (because then splitting would lead to better absorption rather than having tens of units in one injection), then splitting your bolus for your main meal and then your dessert is fine and something I do more often than not. It’s basically the same as having it all up front, but you might see a slight difference in your blood sugars, depending on the time between the injections.

 

[helli]

To my knowledge, smaller doses are not absorbed any quicker.
The main difference is that you are spreading the activity of the insulin out.
Let’s say insulin starts working straight away and reaches it’s peak strength in 30 minutes, if you had a relaxed meal of multiple courses over an hour, the insulin you took at the start would be active before you finished your dessert so you may go hypo.
The other time when we may split our insulin dose is if we eat something with high carbs and high fat like a pizza or a curry or a pasta with a creamy sauce. The fat in the meal will slow down the digestion of the carbs so some of us inject part of the insulin dose up front and the rest of the insulin and hour or two later. Like many things in diabetes, it takes some trial and error to get the timings and ratios right for you.

 

[mashedupmatt]

As has already been said, there is nothing wrong with splitting the dose and for certain foods (takeaway pizza for me) it is worth considering it - but it is all very individual and requires a lot of trial and error

 

[everydayupsanddowns]

I have a suspicion (little more than that) that smaller doses ought to absorb faster. And I can’t remember whether that is being fuelled by something authoritative I have read, that I can’t really remember (eg John Walsh/Ruth Roberts ‘Pumping Insulin’), or facts about animals/nature, or just a hunch.

To me it feels like the surface area of the injected insulin in comparison to its volume ought to impact the speed of absorption? Like how polar bears find it easier to survive in arctic environments because there’s a lot more volume of bear, and less edge of bear getting cold. Smaller mammals like Fennick Foxes find it harder, because they get colder faster. In the same way, the insulin feels like it should be absorbed by contact with tissue, and comparatively the higher proportion of droplet thats in contact with skin vs volume of the ‘depot’ of insulin feels like it ought to be slurped up faster. A wide flat puddle evaporates faster than a deeper puddle in a crevice.

That would be my hypothesis anyway!

 

[helli]

@everydayupsanddowns i understand your theory but my gut feel is that is works for doses higher than 5 units.
I don’t know whether this is because higher doses imply higher carbs which leads to higher BG peak and higher BG comes with insulin resistance so the dose takes longer to work or may not be enough.
But I may be adding 2+2 and getting 6.

 

[John Gray]

The Mounjaro KwikPen appears to have a devious mechanism within it which causes problems if you do not inject the full 60 'clicks' worth of liquid (the direct equivalent of injecting 60 units of insulin) in a single operation. Of course Mounjaro is supposed to operate over a complete week [has anyone seen any graphs of this, by the way?].

 

[SimonP]

I have a suspicion (little more than that) that smaller doses ought to absorb faster. And I can’t remember whether that is being fuelled by something authoritative I have read, that I can’t really remember (eg John Walsh/Ruth Roberts ‘Pumping Insulin’), or facts about animals/nature, or just a hunch.

To me it feels like the surface area of the injected insulin in comparison to its volume ought to impact the speed of absorption? Like how polar bears find it easier to survive in arctic environments because there’s a lot more volume of bear, and less edge of bear getting cold. Smaller mammals like Fennick Foxes find it harder, because they get colder faster. In the same way, the insulin feels like it should be absorbed by contact with tissue, and comparatively the higher proportion of droplet thats in contact with skin vs volume of the ‘depot’ of insulin feels like it ought to be slurped up faster. A wide flat puddle evaporates faster than a deeper puddle in a crevice.

That would be my hypothesis anyway!

That's my gut feeling too - surface area is proportional to r^2 but volume is proportional to r^3. This is the same reason that tall people are unfairly penalised by the BMI calc.

However, if there's any leakage, which I assume is generally a fixed amount as it's not under pressure, then you could potentially lose a larger proportion of your injected quantity for smaller injections.

The jury is still out! 🙂