Hi
@James472 ,
Appreciate your thoughts on this..
OK, in the early days of this “potency loss.” I stuck with the cartridge, increasing the dose by increments of 2u thinking my requirements had increased..
Then when I changed the cartridge, was “captain hypo” needing very little bolus on the new basal dosage. So I reverted back to my original set Lantus dose & was fine.
I’m mindful of where I keep both pens in use outside the fridge & have no issues with Novorapid.
I’ve tried keeping the Lantus pen in the fridge, taking the sting on injection from cold. Rotating injection sites as always. Using Frio wallets.. All insulin boxes are in a Tupperware container in the fridge, so no chance of touching the sides of the unit.
Not all cartridges do this I can’t even pin it to one batch or box..
I go though a cartridge every 18 days, (including air shot units.) the last one worked all the way. I started a new one 2 days ago..
There is a little play in a cartridge for “sick day rules.”
In the summer, or warmer climates on holiday.. I’m more insulin sensitive & need to ease off my basal dose by a unit or 2? (Especially when grafting in a sweat box or sun trap. ) However, the mysterious potency loss can happen at any time leaving me chasing errant BG readings in the 20s (meter agrees with Libre for me.) with Novorapid & generally “busking” all eyes & teeth through a rough day…
Since the advent & use of the Libre in the last few years. My observations have become clearer regarding explanation with an endo or DSN on the data as opposed to the old meter logs..
But alas, they believe there is “no such animal…”
I’ve been pushing “this” for years.. I might as well shew them pictures of where I work & suggest it’s “Area 51.”
Hi
@Jaylee ,
I'll go through your points again:
1. It is theoretically possible that you 'are' genuinely getting occasional 'duff' cartridges, but I can see why your support teams would find that tough to consider. It wouldn't be the first time things have gone wrong at a source manufacturing site, but it is unlikely, particularly since these guys have got to be very careful when manufacturing something so critical as insulin. So that one unlikely, plus, if it was that, I feel it would be more likely to affect the whole pack of 5, rather than just 1 in the pack.
2. In the same way you are taking fridge conditions & separation into effect, it is possible that there's a slight oversight of that happening in the pharmacy, or the pharmacist's distribution supplier - fridges (even at the professional level) do at some point start to perform less well, and it can sometimes take a little while to realise that some of the storage area is being subject to higher temps. Or, if they're storing the Lantus stock at a worse section of the chiller, then cartridge no.1 of 5, or cartridge 5 of 5 could be warmer. But again, these dudes are in the chilling business, so my money's not on that. Again, didn't really have Lantus down as an insulin that is 'over-sensitive' to temps.
So those two can't be ruled out, but I'd say - less likely.
3. The summer, or warmer climes ? OK, you know where I'm heading now !

I remember noticing this phenomenon over the years (some chance these days !), and others have said this for years. If, as I am theorising, there is another 'thing' going on, then maybe the warmer climate is helping. If it was dust mites in clothing fabric, then the UV from sun will quieten them down after (I think) 20 minutes. There are 2 good plusses to hanging washing out on outside lines - the fresh air blow is good for stuff, plus the UV from sun kills dust mites after 20 minutes. Although, as I theorised before, it feels to me like a dead dust mite only becomes food for the next generation. If it's demodex mite related, again, the sun beating down on you might keep them in order down the hair follicles.
If you do a search on-line for where diabetes is most prevalent, and I looked 2 years back, I seem to recall a large number of areas with particularly high percentages were islands in the pacific (with > 20%) and various other places. There will be a reason for those locations I'm sure, but I don't know what - could be high humidity maybe ? Might be the nutritional diet, I don't know ?
4. If you go through a cartridge every 18 days, are you on similar to what I was used to - i.e. 16 units basal ? If so, that's less than 1 unit per hour ?
So, if you're ending up with a BG of 20, does that mean you've left it to gradually reach 20, or has it happened quicker than that ?
What I'm saying is ......... (my head's starting to hurt now, with the maths) for me, if my Lantus 16 units stopped working, it would take quite a few hours to reach BG of 20 (if I was in normal diabetic mode, which I'm far from right now !). Say I was at BG 6, and stable, no food, no lingering bolus, it would take me 10 hours to hit BG 20.
I realise that doesn't necessarily apply to you
@Jaylee
So does it take you 10 hours to hit that BG 20 ?
And, is there any associated nasal rhinitis ?
Or, could it be that it's actually an injection site issue, and more a reflection of the NovoRapid bolus going into a wrong injection site ?
I'm not sure if I've misinterpreted what you've explained there ?
The other things you were talking about in the previous post, the fluctuations, could be affected by ordinary / every day stuff, connected with this 'unknown' thing I'm chasing. For instance, I found on several occasions, that things can improve when you wash the duvet cover - not every time, but on a significant number of times, it has been noticeable. Don't get me started on all that !

If my thoughts on there being some connection to hair are right, the problem with bedding is, a hair or two could easily go unnoticed for a while if it's on the wrong side of the duvet cover, and / or inside the tuck of the pillow case !
See if you can note down anything else that happens when your cartridge potency worsens - change of clothing, change of bedding, garden earth / plant material under soles of shoes, recent haircut, with a lot of cut hair on a scarf or a collar etc. etc. etc. I will try and make a list soon, of all the possibles I'm considering, then you'll know for sure I've flipped.
I've got a bunch of tests I'd like to do, to see if there's any mileage, but while I'm so rollercoaster, there's hardly any point right now - coz I won't know if the test has worked, or if it's just normal rollercoaster. But once things quieten down, one thing I had planned to do was Cherry Tomatoes - on the vine.
I thought on a couple of occasions, I'd linked some very heavy nasal rhinitis with having allowed tiny fragments of the vine leaves / stalk to fall on floor in kitchen, and only noticed it after the rhinitis started. But again, it could have been a misinterpretation, with the cause being other things ? If anyone wants to volunteer for that test, I won't say no ! But if you don't have my population numbers, you may have to allow a few hours !