Changing over from mixed insulin to a CGM regime.

[Elooned]

Hi, I was wondering if anyone could tell me how you change from a mixed insulin to be able to use a CGM system?

 

[Elooned]

Hi,

I was just wondering if anyone could tell me what the usual steps in the UK would be to change over from a mixed insulin regime to a CGM system would be?

Thanks

 

[EllieM]

Hi @Elooned and welcome to the forums.

Can I just clarify what you mean by your question.

As a UK T1 I believe you should automatically qualify for a libre 2 or dexcom ONE glucose monitoring system, irrespective of your insulin regime.

As regards insulins, your profile says you are on humulin MS so I'm guessing you are on fixed doses of that and have to have fixed carbs at specific times of day to match your insulin? (I was on that sort of regime as a child, pre glucometer)

It is more common for T1s to be on a basal/bolus regime of multiple daily injections (MDI)
The basal insulin is a long acting insulin calculated to keep you level through the night. The bolus or short acting insulin is then given both before meals (varies with your carbs and any correction dose you need) and also as separate correction doses if you are unexpectedly high and want to bring yourself down before a meal. It gives a lot more control to the diabetic, because you decide your doses, though your clinic should help you work out your dosing and ratios (how many carbs per unit of insulin) when you start.

There is a DAFNE course that many UK T1s find useful to help them learn how to manage their dosing.

However, you may be wondering about insulin pumps that use cgms to help tell the pump how much to inject??? Not a pump user, so I can't help on this, but my understanding is that that is still a work in progress as regards UK T1s getting access.

Hope this helps, most of the UK T1s are asleep now, but if you ask more questions you will get answers (just maybe not till they wake).

 

[Elooned]

Hi @EllieM,

Thank you for the reply. What's happened is that after seeing the omnipod 5/dexcom 6g system I asked my diabetic nurse if I could go from a 2 injection a day M3 insulin regime to the omnipod 5 system. She said I could but first said I would need to become familiar to the Libre blood glucose monitor (which I started using in Feb) and then change from the mixed M3 insulin to a separate slow release and rapid insulin. Which I've just started to do so now.

What I want to know is do you have to go through this step to get onto a CGM system? If the CGM system just uses rapid insulin and as a closed loop/insulin pump system which is self regulating up to a certain degree which is meant to help regulate your blood glucose levels more efficiently. Why would I need to do this interim step?

Just for context, I have been an insulin dependent diabetic for 30 years and the only reason I was given the Libre blood glucose monitor is because I asked about moving onto the Omnipod 5 system. Otherwise, I'd have had no support or intervention by my health board. However, since going onto the Libre blood glucose monitor I have been able to regulate my blood sugar levels much better and ad a result I had a retinal bleed that led to me just recently having to have urgent retinopathy correction surgery on both eyes. From the research my partner found, the CGM can reduce additional diabetes related issues by 30%. So, going forward I would like to do this.

Thank you again for the reply.

 

[Deleted member 527103]

@Elooned I think you are confusing the term CGM with Closed Loop.
You have a CGM today - the Libre is a CGM.

As you have described, a Closed loop system will regulate your blood sugars. However, it only regulates your basal/background insulin. Even the fastest injectable insulins available today do not work fast enough to react to food that you eat. You still have to tell your pump how many carbs are in your meals to calculate the bolus insulin dose.

Therefore, I assume the reason for going through the "interim" step is to learn about carb counting and adjusting your bolus dose based upon what you eat.

 

[Elooned]

Okay, that makes sense. However, I've been reading about the calculations around dosage and unit amount calculations, and the nurse was well off. I am a maths teacher, so doing calculations is my bread and butter so to speak. I've been working out my carbs for years, so it's not like I'm a novice. The Diabetic nurse made out that the reason I had to go onto this system was to see if I could manage it. As if this was some sort of eligibility criteria. As far as I'm aware the recent NICE guidelines is that all type 1 diabetics should be going onto a closed loop system. So, this seems to be more a financial issue than a medical one.

Also, the units the nurse suggested were out by nearly 30% for the slow release insulin.

So, going back to my original query, is it mandatory for someone moving from a mixed insulin regime to have to go onto a multiple separate slow and rapid release insulin regime to get to the ultimate step of going onto a closed loop system?

 

[Rokaab]

So, this seems to be more a financial issue than a medical one.

Most of it is entirely financial cos unfortunately these things ain't cheap
Which is why not everyone gets pumps - and you have to prove that you need one rather than just want

Also, the units the nurse suggested were out by nearly 30% for the slow release insulin.

Well everyone is different, they have to make a guess, and a lower guess is better than a higher guess

So, going back to my original query, is it mandatory for someone moving from a mixed insulin regime to have to go onto a multiple separate slow and rapid release insulin regime to get to the ultimate step of going onto a closed loop system?

They probably need to know you can use/deal with the basal/bolus regime in case of pump failure - because yes it can and does happen - in fact mine failed about 3 weeks ago - had to briefly go back to pens (though the replacement was with me dead fast)

 

[Elooned]

Thank you @Rokaab for the response. So, I guess what you're saying is that there probably isn't any medocal reason as to why this step needs to be taken it is motivated more by risk aversion and financial constraints. Sounds about right.

 

[EllieM]

Thank you @Rokaab for the response. So, I guess what you're saying is that there probably isn't any medocal reason as to why this step needs to be taken it is motivated more by risk aversion and financial constraints. Sounds about right.

Not a pump user but I've read a lot of threads by UK T1s who've had to wait years and go through all sorts of hoops to get them.
Good luck.