Diabetes type 1 (young people)
Continuous Glucose Monitoring (CGM)
Continuous Glucose Monitoring (CGM) involves wearing a small device that monitors the glucose levels day and night. The CGM device consists of three parts:
- a small sensor that sits just under the skin (which is ‘like a pump cannula’);
- a transmitter (this is attached to the sensor and sends data wirelessly to the display device) and
- a display device (this shows whether the person’s glucose levels are high, low or within range).
CGM can be used by those on insulin pump therapy, on insulin injections, and by people taking other diabetes medication. Some CGM devices have alarms to indicate when the glucose levels are too high or too low.
Is it easy to, to get used to it? Is it easy to use?
Yeah it’s definitely easy. It comes in two parts. You slot it together. You, it’s got an inserter. You put it straight on your skin. You press it down and that’s it and you lift the inserter off and it’s there. It’s easy to use. You just scan it. There is nothing to it.
You, do you need to, to go to the? It’s done by a nurse.
No you can do it yourself every 14 days. It’s just like having an insulin pump canula.
Ok and when you say you scanned it, how do you do that? Do you have another machine that?
Yes so I have a little handset that’s the size of a, half an I-phone and I click a button and scan it and it comes on and it beeps and it tells me what my blood sugar levels are.
Ok and you can do that every time?
Yeah through clothes, through coats, anything.
Ok and as many times as you want?
Yes as many times.
Young people we spoke to felt that using CGM has really helped with the management of their diabetes and they found it easy to use. They felt that using CGM was less time consuming and intrusive than doing blood sugar tests or the ‘finger prick test’. But they also understood that what the CGM sensor measures is the glucose in the interstitial fluid (the fluid between the cells) and not the sugar levels in the blood.
I still keep that because the guidelines say that if you’re ever very low or ever very high the most accurate reading will be from your blood. So this is when you have a CGM or an FGM it reads from your interstitial fluid and is meant to be kind of a bit of a delay. So if you blood sugar is changing rapidly they always advise that you test like a finger prick and if you’re driving as well if you. Under the DVLA you need to do it with a finger stick so I do do my finger prick tests but I probably used to do my finger prick test four times a day. I now maybe do it once, twice. A lot of the times I will just rely on this because I’m just, I trust it and I am happy with the readings. And also I think what’s great is that I test my blood sugar so much more now. I’m so much more aware of what it is all the time because it’s not that hassle of doing it and I actually inject a lot more now. So I probably do a lot more than four injections a day because I’m just keen to sort of keep it more in range. And I think cos you can see a graph of your bloods out of range or out of target it makes you more motivated to sort of bring them down. And you can see them come down so, yeah I do do a lot. My, it’s kind of helped me to up my management which has been good.
Young people said that the use of a CGM has seriously reduced the need to do finger prick tests several times a day. But they still depend on blood sugar tests when trying to understand why they are going high or low. They also understood that it is a DVLA requirement to always do a finger prick test before they drive to check if their sugar levels are within the permitted range (5 or above).
Ok and how do you feel about that, finger testing?
Lewis: I still have to finger test sometimes cos this isn’t. Sometimes it can be a bit out like after a new sensor. It can be a bit out because it’s obviously a new sensor and it needs to like warm up and get used to the…
Father: Settle in.
Lewis: Settle in. That’s when I start to test. Apart from that when you’re having a new sensor it’s actually quite accurate isn’t it so you don’t have to test that much.
Father: I’d say you’ve got I mean at the peak of testing it would have done anywhere between 5, 15, 20 times a day. Because obviously you’re used to have a lot of variable glucose levels but now with that looking to the history of his meter it’s probably testing two maybe three times a day if that because we’re comfortable and he’s comfortable that it’s that reliable and accurate to use.
Mother: You are advised to test them if it alerts you as hypo or high so you can base your decisions on those readings. It is advisable. So I suppose we should say that’s the proper way of doing it.
So I am using the Freestyle Libre and I’ve used it for 6 months. And I change it every 14 days and I check my blood sugar levels through it instead of having to finger prick every time through the fluid in my body. So I scan my device on the [Libre]. And it tells me what my blood sugars are and it shows a graph of what your blood sugars have been and if they are rising or if they are falling and that helps a lot with management because you have more information than just with a finger prick.
So it means you don’t do any finger prick now?
I have to finger prick before I drive because that’s the legal requirement that you have to finger prick before you drive. And whenever I’m really high or really low I’ll just double check it with my finger pricker but for every day-to-day scans I don’t, don’t double check it with my finger pricker at all.
Ok and do you take this graph to your doctor to, to see and discuss?
Yeah so I take it along with my insulin pump to my diabetes clinic and it gives them a lot more information about what my blood sugars have been doing as well. So they can compare that to my readings on my handset. So it helps them as well as it helps me.
Ok and how do you feel about using this device?
I love it. [ha ha] It’s the best thing that I’ve used. It’s just. It allows me to have so much more freedom because with finger pricking you have to take so much time to get your strips out and it’s quite intrusive on your fingers. My fingers were getting quite sore before I started using [Libre]. And it doesn’t bother me whatsoever.
Ok so
Having it on my arm.
The data provided by the CGM is very useful to find out if the insulin therapy is working well. Young people said that the CGM device has made it easier to understand their glucose pattern better and identify issues such as the ‘dawn phenomenon’ which, before using the device, could have been attributed to having the wrong insulin regime rather than a simple spike in their blood glucose levels at the point of waking up. The use of CGM and knowing how their blood sugar levels are doing throughout the day and night made the young people we spoke to feel ‘more in control’ of their diabetes and ‘less scared of doing an extra insulin shot when going low’.
Mother: It was different back then though because pumps still weren’t as part… they weren’t as common as they are now.
Father: And even now they are not common really.
Mother: Yeah and we hadn’t even thought. It hadn’t crossed our mind had it and it was only because the team said, “Look we don’t think we are going to get his levels under control with injections.” And we just went with the advice of the healthcare professionals at that. They felt that would be best for Lewis so we agreed with it. We really didn’t give it much thought. We weren’t against pumps but we weren’t, we want a pump.
Father: Didn’t really know that much about the did we?
Mother: No
Lewis: I didn’t even know they existed.
Father: No.
Lewis: I was only four-six -ish.
Mother: So then they put that blind CGM on Lewis to get some data and it showed that there was no chance of getting any control. His, his bloods just swung from…
Father: Two to 20
Mother: Yeah and there was no pattern, no pattern at all but it meant that his average was always ok because it met in the middle. His A1c so if they were just looking without the CGM if they were just looking at his data for like HbA1c
Father: That would say he was managing well.
Mother: They would have said it was ok.
Ok.
Mother: So the CGM really helped because they could prove that actually his levels were swinging and there is no pattern. So we couldn’t inject differently.
So we are, after around two years it was decided it was better for him to go on the pump?
Mother: Yeah I think it was about 18 months give or take. Yeh.
Father: I think it was the February it was decided he might they were looking to, wouldn’t they to put him on a line continuous glucose monitor. And it was another 3 or 4 months while funding was arranged. And then it was at the two year mark he went on it then wasn’t it?
I’d say I do a lot more like correction doses now. So again before like if my blood sugar was at 10 or 12 I’d probably just leave it whereas now I’m quite conscious that I want to get it down to 5 or 6 or whatever to keep it in range. So I’m much happier sitting at a lower level now, like confidence wise than I used to be. I used to want to just stay at 10 or 12 just in case I’d have a hypo. But I’m a lot more confident these days. If I’m sitting at 4 or 5 I know that I can just have an energy tablet or two or, a bit of Lucozade and I’ll be ok. So yeah that’s something that I had to sort of overcome myself as well I guess but I kind of made sure that I put in the effort to, to do it. I used to, I used to be quite worried about like overnight hypos as well but I’ve made myself sort of go to bed on a decent number and not. So what I used to do is over-eat before I go to sleep to make sure that I wouldn’t hypo. So I’ve stopped myself doing that and just set alarms in the night to sort of check my blood and then slowly stopped setting alarms and just not told myself, “Don’t worry if you have a hypo you’ll wake up.” Because I do usually wake up. I am lucky. I do get the symptom so I’m lucky in that sense. And yeah I’m a lot better now at going that if my number is 7 or 8 I won’t go and eat the whole fridge before I go to bed [ha]. I’ll just go to bed and wake and not run 12 hours of numbers overnight.
Ok. So did you, with the CGM were you scanning the CGM during the night as well?
Yeah so what the CGM does as well which is again helpful. It, it logs sort of the past 8 hours of your data. So if you’d scanned it before you went to bed and then you woke up in the morning it would show you what you did overnight. So what it was showing me was that when I ate loads before I went to bed I’d spend 12 hours out of range. And again I slowly dropped down towards the end so maybe I’d wake up on 7 or 8 whereas before I’d say, “Oh fine I’ve been sitting at 7 or 8 all night.” But I haven’t I’ve been really high all night and again that that made me realise I need to stop that because that’s 12 hours a day times 365 is a long time to be out of range. So yeah, so that’s really helpful. So I can always see what my bloods have done overnight now because I check it first thing in the morning. But when I was first starting to get myself into this sort of habit I guess of going to bed and not having high blood sugars I would wake myself up at sort of 3 am and check my blood with the scanner and just check that I was ok. And then it would be so easy because I just sort of pick it up from the side. Do it. Check that I was ok and just go back to sleep. So didn’t have to get up and do my blood sugar and all that so.
But you are not doing that now?
No I’ve just kind of got the confidence to, to go to sleep and. I’ll check it in the morning and see what it’s been but I’m trying to, yeah stop myself from worrying too much about that kind of thing.
Young people we talked to use CGM data to produce graphs which show how their blood sugars have been doing within a certain period of time or, help to identify the periods when they are likely to go hypo or hyper. The information can also help them understand the relationship between exercise and diet and how they can affect blood sugar levels.
Sometimes you can see your bloods spike up really high and sometimes you can just see it spike a little bit. But when you do the finger prick test say it’s spiked but then came back down you wouldn’t ever see that spike. You’d only see it sort of two hours after where it’s spiked and come back down. So you don’t see the effect.
I found that quite a lot with running as well. So I’ve been doing a lot of running recently and now what’s amazing for me is I can just test my blood as I’m running so I can just scan my arm and just check if I’m ok as I am running along which is fantastic and not having to stop. But again things that I wouldn’t have noticed so I usually try and work out how much carbohydrate I’d need for a long run. And I’d see a lot of patterns where if I’d run in the evening it will be completely different to if I ran in the morning. And if I ate too many carbohydrates you’d see this massive spike of my blood sugar but because I was doing exercise it would come back down quite quickly. So by the end of the run I’d be back in range and, you know, but it had gone up and down in that run whereas if I didn’t have that I would have just pricked my finger at the end and been like, oh perfect. I’ve just stayed from 7.0 to 7.0 [laugh] but I haven’t. Yeah. So it’s really interesting
You’re up and down.
Yeah so it’s really interesting to actually see how different things affect you and you kind of grow more aware of what you’re doing and what you’re eating and stuff.
There are various types of CGM devices on the market but the main consideration when purchasing one seemed to be its cost. The young people we talked to said that they were self-financing their CGM and that they go for the one that is affordable and reliable. Lewis’s parents bought him the CGM device but the hospital funds the sensors. Initially, Lydia got the monitor and sensors on a clinical trial but after it finished, she decided to continue using it so now she pays for it herself.
Katie would ‘very much like’ to have a CGM but she explains that as a full-time student she can’t afford one. She knows how useful they are in helping with diabetes management and hopes to be able to afford one in the future, when she is working.
Lydia talks about her CGM and how she uses it.
Lydia talks about her CGM and how she uses it.
SHOW TEXT VERSION
PRINT TRANSCRIPT
Yeah it’s definitely easy. It comes in two parts. You slot it together. You, it’s got an inserter. You put it straight on your skin. You press it down and that’s it and you lift the inserter off and it’s there. It’s easy to use. You just scan it. There is nothing to it.
You, do you need to, to go to the? It’s done by a nurse.
No you can do it yourself every 14 days. It’s just like having an insulin pump canula.
Ok and when you say you scanned it, how do you do that? Do you have another machine that?
Yes so I have a little handset that’s the size of a, half an I-phone and I click a button and scan it and it comes on and it beeps and it tells me what my blood sugar levels are.
Ok and you can do that every time?
Yeah through clothes, through coats, anything.
Ok and as many times as you want?
Yes as many times.
Sophie does a finger prick test every time before driving and when she finds she is going ‘low’ or ‘high’. At all other times she is happy to get her readings from her CGM.
Sophie does a finger prick test every time before driving and when she finds she is going ‘low’ or ‘high’. At all other times she is happy to get her readings from her CGM.
SHOW TEXT VERSION
PRINT TRANSCRIPT
Lewis says he does a couple of finger prick tests a day but more often when using new CGM sensors. Before the CGM he was doing up to 20 tests a day.
Lewis says he does a couple of finger prick tests a day but more often when using new CGM sensors. Before the CGM he was doing up to 20 tests a day.
SHOW TEXT VERSION
PRINT TRANSCRIPT
Lewis: I still have to finger test sometimes cos this isn’t. Sometimes it can be a bit out like after a new sensor. It can be a bit out because it’s obviously a new sensor and it needs to like warm up and get used to the…
Father: Settle in.
Lewis: Settle in. That’s when I start to test. Apart from that when you’re having a new sensor it’s actually quite accurate isn’t it so you don’t have to test that much.
Father: I’d say you’ve got I mean at the peak of testing it would have done anywhere between 5, 15, 20 times a day. Because obviously you’re used to have a lot of variable glucose levels but now with that looking to the history of his meter it’s probably testing two maybe three times a day if that because we’re comfortable and he’s comfortable that it’s that reliable and accurate to use.
Mother: You are advised to test them if it alerts you as hypo or high so you can base your decisions on those readings. It is advisable. So I suppose we should say that’s the proper way of doing it.
Lydia does the finger prick test before driving, but most of her readings are based on CGM data. The CGM graphs are a source of information to her care team.
Lydia does the finger prick test before driving, but most of her readings are based on CGM data. The CGM graphs are a source of information to her care team.
SHOW TEXT VERSION
PRINT TRANSCRIPT
So it means you don’t do any finger prick now?
I have to finger prick before I drive because that’s the legal requirement that you have to finger prick before you drive. And whenever I’m really high or really low I’ll just double check it with my finger pricker but for every day-to-day scans I don’t, don’t double check it with my finger pricker at all.
Ok and do you take this graph to your doctor to, to see and discuss?
Yeah so I take it along with my insulin pump to my diabetes clinic and it gives them a lot more information about what my blood sugars have been doing as well. So they can compare that to my readings on my handset. So it helps them as well as it helps me.
Ok and how do you feel about using this device?
I love it. [ha ha] It’s the best thing that I’ve used. It’s just. It allows me to have so much more freedom because with finger pricking you have to take so much time to get your strips out and it’s quite intrusive on your fingers. My fingers were getting quite sore before I started using [Libre]. And it doesn’t bother me whatsoever.
Ok so
Having it on my arm.
Lewis’s Care Team secured funding for his insulin pump after the continuous glucose monitor showed that his insulin therapy was not working well for him.
Lewis’s Care Team secured funding for his insulin pump after the continuous glucose monitor showed that his insulin therapy was not working well for him.
SHOW TEXT VERSION
PRINT TRANSCRIPT
Father: And even now they are not common really.
Mother: Yeah and we hadn’t even thought. It hadn’t crossed our mind had it and it was only because the team said, “Look we don’t think we are going to get his levels under control with injections.” And we just went with the advice of the healthcare professionals at that. They felt that would be best for Lewis so we agreed with it. We really didn’t give it much thought. We weren’t against pumps but we weren’t, we want a pump.
Father: Didn’t really know that much about the did we?
Mother: No
Lewis: I didn’t even know they existed.
Father: No.
Lewis: I was only four-six -ish.
Mother: So then they put that blind CGM on Lewis to get some data and it showed that there was no chance of getting any control. His, his bloods just swung from…
Father: Two to 20
Mother: Yeah and there was no pattern, no pattern at all but it meant that his average was always ok because it met in the middle. His A1c so if they were just looking without the CGM if they were just looking at his data for like HbA1c
Father: That would say he was managing well.
Mother: They would have said it was ok.
Ok.
Mother: So the CGM really helped because they could prove that actually his levels were swinging and there is no pattern. So we couldn’t inject differently.
So we are, after around two years it was decided it was better for him to go on the pump?
Mother: Yeah I think it was about 18 months give or take. Yeh.
Father: I think it was the February it was decided he might they were looking to, wouldn’t they to put him on a line continuous glucose monitor. And it was another 3 or 4 months while funding was arranged. And then it was at the two year mark he went on it then wasn’t it?
The CGM has helped Sophie to become more confident at managing her diabetes and she intervenes when necessary e.g. doing insulin correction doses.
The CGM has helped Sophie to become more confident at managing her diabetes and she intervenes when necessary e.g. doing insulin correction doses.
SHOW TEXT VERSION
PRINT TRANSCRIPT
Ok. So did you, with the CGM were you scanning the CGM during the night as well?
Yeah so what the CGM does as well which is again helpful. It, it logs sort of the past 8 hours of your data. So if you’d scanned it before you went to bed and then you woke up in the morning it would show you what you did overnight. So what it was showing me was that when I ate loads before I went to bed I’d spend 12 hours out of range. And again I slowly dropped down towards the end so maybe I’d wake up on 7 or 8 whereas before I’d say, “Oh fine I’ve been sitting at 7 or 8 all night.” But I haven’t I’ve been really high all night and again that that made me realise I need to stop that because that’s 12 hours a day times 365 is a long time to be out of range. So yeah, so that’s really helpful. So I can always see what my bloods have done overnight now because I check it first thing in the morning. But when I was first starting to get myself into this sort of habit I guess of going to bed and not having high blood sugars I would wake myself up at sort of 3 am and check my blood with the scanner and just check that I was ok. And then it would be so easy because I just sort of pick it up from the side. Do it. Check that I was ok and just go back to sleep. So didn’t have to get up and do my blood sugar and all that so.
But you are not doing that now?
No I’ve just kind of got the confidence to, to go to sleep and. I’ll check it in the morning and see what it’s been but I’m trying to, yeah stop myself from worrying too much about that kind of thing.
The ability to scan her CGM at any time and during different activities has made Sophie aware of the constant changes happening in her blood sugar levels.
The ability to scan her CGM at any time and during different activities has made Sophie aware of the constant changes happening in her blood sugar levels.
SHOW TEXT VERSION
PRINT TRANSCRIPT
I found that quite a lot with running as well. So I’ve been doing a lot of running recently and now what’s amazing for me is I can just test my blood as I’m running so I can just scan my arm and just check if I’m ok as I am running along which is fantastic and not having to stop. But again things that I wouldn’t have noticed so I usually try and work out how much carbohydrate I’d need for a long run. And I’d see a lot of patterns where if I’d run in the evening it will be completely different to if I ran in the morning. And if I ate too many carbohydrates you’d see this massive spike of my blood sugar but because I was doing exercise it would come back down quite quickly. So by the end of the run I’d be back in range and, you know, but it had gone up and down in that run whereas if I didn’t have that I would have just pricked my finger at the end and been like, oh perfect. I’ve just stayed from 7.0 to 7.0 [laugh] but I haven’t. Yeah. So it’s really interesting
You’re up and down.
Yeah so it’s really interesting to actually see how different things affect you and you kind of grow more aware of what you’re doing and what you’re eating and stuff.
Some young people were told about CGM by their care team but most of them have got to know about CGM through social media.
Lewis’s parents use a remote monitoring system called NightScout that allows Lewis and his parent’s access to Lewis’s CGM data via an android phone. This project is developed and maintained by an online community of parents of children with Type1 diabetes and it is free and open to all.
Last reviewed December 2017.
Last updated December 2017.
Lewis’ parents talk about the receiver created by and for Type1 diabetes people. They feel that this remote monitoring device is helping them as a family.
Lewis’ parents talk about the receiver created by and for Type1 diabetes people. They feel that this remote monitoring device is helping them as a family.
SHOW TEXT VERSION
PRINT TRANSCRIPT
Mother: Basically some parents and people with Type 1 are really good with like computer programming. And you are able to connect your sensor instead of using the normal official receiver you can just carry a little box.
Ok.
Mother: And it will just upload your results to the phone instead
Father: Which can then compare to the watch which
Mother: Yeah which he’s got on his watch but when he’s at school we can see it on our phone. So if he has a problem at school he could ring us if he needed to and then we could see what the pattern is. But it is not an official thing at the moment.
Father: Also it means like because the sensor that he uses is pretty accurate if he didn’t have it, he felt high or low he’s have to be testing his blood sugars a lot more regularly. But obviously with the continuous glucose monitor with it on his watch he can just have a quick glance, see if he’s ok and away he goes. Or if he bleeps high or low he can then take action a bit more discretely because obviously with the fitting in concerns
Mother: Yes on his arm he just does that [action on video]
Father: He can then obviously you know pop a couple of glucose tablets or a few button presses for the, for the correction without messing about and everyone going, “Oh what are you doing?” Because obviously we all want to fit in when we’re young. I mean we still do as adults and you don’t want to be different even though we all are different.
We used it [remote monitoring box] in combination with the official receivers and in actual fairness the unofficial homemade DIY version was better than the official version and far more reliable and accurate. So we, we stick with that and it works. And
Mother: And it really helps as a family when he’s not with us
Father: Yeah
Mother: Because we can see…
Lewis: Don’t have to worry
Mother: …we don’t keep looking because then uit’s an invasion of his privacy but if you were to ring us to say…
Father: I’ve got a problem.
Mother: I’ve got a problem.” Then we can look at it, you know.
Father: And go “Right looks like so and so is going on. What we need to do is this.” And you do it. Because we never really text you or bother you do we saying, “You’re high, you’re low. You’re high, you’re low.”
Lewis: No, but when it gets a bit too high that’s when you start to text me if I don’t do anything.
Father: We will if you’re really, really high.
Lewis: But not that much, yeah.
Mother: Night time is really good as well because before we used to have to set our alarm and come down and just check in the night. Now we don’t have to because that facility will alarm if there is a problem. So we only get woken up if there is a problem as opposed to being woken up all the time. So it’s really helped in that respect.
Father: His healthcare team know. I mean the first time Lewis went with this particular version his consultant called in a few others saying, “Come and look at this. Come and look”. He was like, “This is amazing. This is brilliant. This is.” And I was like, you know, this is what parents have done. It also pushes the big pharmaceutical companies to push their own.
Mother: Yeah. They could do this.
Father: Their own designs.
Mother: If they chose to though you know.
Last reviewed December 2017.
Last updated December 2017.
Copyright © 2024 University of Oxford. All rights reserved.