Showing posts with label review. Show all posts
Showing posts with label review. Show all posts

Posted by on Thursday, 31 December 2020

Hype or Hope? Dexcom, Tandem tSlim review and 2020 round-up

Wait... hang on... December 31st? That can't be right! Have we actually had a year this year? And how come any of the things that happened this year seem to have happened at least 18 months ago? No time has passed. But it has passed at a snail's pace. And at the same time we've all become accustomed to living completely different lives.

Doing a sort of round-up post for the year that never happened doesn't seem worthwhile. There are only so many times I can talk about avoiding a Zoom-based diabetes thing before I'm going to run out of waffle. Yes even me.

tldr; 2020 was a bit pants. But I really like the tSlim and Dex.

Tandem tSlim Insulin Pump
Tandem tSlim with Dexcom G6
Out with the old
I've been meaning to write a post or three about my experiences of the Dexcom G6 and my switch to the Tandem tSlim:x2 (and subsequent upgrade from Basal IQ to Control IQ) since the Summer, but for all sorts of reasons that series of posts never arrived. I have lots of pics of pump and graph cluttering up my phone that were apparently going to eloquently show something or other, but it's all so long ago now that I can't really remember what it was I was going to say.

I am self-funding Dexcom G6 sensors, and it was the first time I had used Dexcom. Such is the relentlessness of the positivity around Dex, that I think secretly I might have been hoping that I wouldn't find it all that special. 

I sprung for the 'starter pack' which gives an official 30-day's worth of coverage before I committed to going for the tSlim, so that if my body chemistry didn't get on with the Dex I could opt for Medtronic's MM670G (or similar) with self-funded Guardian G3 sensors. I had always got on well with Enlites and to some extent G3s too, and I was pretty sure that I would have got on well with the MM670G if that was what I'd gone for.

Inserting the Dexcom sensors was really straightforward, and initially I ran the sensors with my iPhone (not yet having taken the plunge on the pump). They restarted easily, and I didn't even have to faff about with unpeeling tapes and removing the transmitter thanks to these instructions. What really struck me though, was how well the factory calibrated G6 tracked fingerstick results from my Contour Next Link 2.4 meter (still my go-to BG meter). The first few days were uncanny. Spooky even. It didn't appear to be hype at all - generally Dexcom was reading only a few decimal points away from any fingerstick I took.

Dexcom G6 lagging a little against hypo recovery
Even a Dexcom G6 lags a little now and then
Reassuringly though, I did see a characteristic post-hypo-sensor-lag on about the 3rd day, where the Dex stubbornly continued bleating about low BG for 5-10 minutes after I was back above 4. So it was a regular CGM and not witchcraft after all. It was just that it was a really good CGM for me.

Joking aside, those early excellent matched pairs (against fingerstick checks) really helped me trust it as a new bit of kit though. 

And even better, while the factory calibration is excellent for me, and I've all but given up cross-checking with fingersticks, if I *need* to recalibrate the Dexcom G6 because it has drifted a little... I can! 

After a few weeks with the Dexcom I was confident to put in my request to switch to the Tandem tSlim when the warranty ran out on Threepio.

Switching to the Tandem tSlim:x2

I affectionately called my first insulin pump robot counterpart 'Artoo' (R2P2 - replacement to my pancreas #2), and kept with the Star Wars theme with my MM640G as 'Threepio'.  This bit of kit promised to be wiser and much more autonymous though, so I've taken to calling it HAL (hybrid automated loop), though of course it would be much funnier if a certain tangerine diabetic had made that joke, [affects creepily calm synthetic robot voice] "What are you doing Dave? I'm afraid I can't let you eat that biscuit..." etc.

Boxed Tandem tSlim
Staying in its box until I was trained up.

As all this was happening while the healthcare system was in some degree of chaos, and all those buzzwords like 'social distancing' were in full flow I wasn't sure how any kind of switchover was going to be able to happen - but in the end, in classic 2020 style I did my pump training via a video call having had the box of goodies delivered direct to my house.

I had a few weeks with Basal IQ before switching to the smarter Control IQ. Both worked well for me, and each have their own idiosyncracies. I have tried to do as little fiddling as possible, taking an initial 7 days to see how each got on when left to their own devices to try to learn what they are good at, and where they struggle. Also learning how to give them the right information to get the best results.

For those outside the Tandem bubble (seriously 2020? another word you've mangled?!), Basal IQ is Tandem's 'predictive low glucose suspend' algorithm, which stops basal insulin in order to try to reduce risk of hypos. Basal IQ is a little more responsive I feel than Smartguard on my MM640G. In that it can turn on and off more quickly, and doesn't have a minumim duration or enforced gap after it has completed. There was a major irritation for me when running the Basal IQ algorithm in that the tSlim moaned at you if you set a 0% TBR, though ot was more than happy to set one itself. Indeed, the tSlim got very grumpy if a TBR was set that was less than 50% of your lowest basal rate. A degree of warbling which was as unwanted as it was unnecessary.

This irritation was short lived though, as I soon upgraded to Control IQ. One of the nice things about the tSlim is that you can plug it into a computer and upgrade the software on the pump. Which means that if they release fancier, smarter, or even just mildly less irritating versions of the pump software, then you don't have to wait until 4 years have passed to take advantage. All I need now is to find the email address of the person to send my Helpful Suggestions to, for inclusion in the next release 😉

Conclusions

I guess I've been on the tSlim a little short of 6 months now, and I can honestly say that I am really glad I made the switch. I loved the MM640G, but the clunkiness of the Medtronic chassis, and some of the million-presses-UX-interface-tedium was wearing me down. Plus the newer G3 sensors were a bit more flaky and prone to overnight calibration requests for me. There are things about the tSlim I would hope would improve - not least the reservoir filling, which is every bit as fiddly as people say. Their reservoirs really need re-engineering so that the 'white dot' behaves more reliably (tSlim users will know what I mean). 

And what of results? Well I've not really that the nerd-energy for much actual data comparison, but going on gut feeling I would estimate that the tSlim has bumped my TIR (time spent between 4.0 and 9mmol/L) by somewhere between 5% and 15%. What used to be a really good week of results is rapidly becoming pretty normal. Control IQ still needs watching as it often responds a little later than I need, and it's not perhaps as 'hands off' as I was hoping it might be, but Control IQ really nails the little adjustments for me. It struggles with circumstances which are a bit wobblier, but it seems very good at optimising gentle drifts. Overnight with Sleep Mode has been spectacularly good. Almost no alarms, and almost always waking in the 5s to 7s.

Gotta be happy with 28/30 days above 80% TIR

It will be really interesting to see if this has had any kind of effect on my HbA1c, but to be honest, I increasingly find A1c a poor proxy for how I feel my diabetes management is going from month to month. It may still be seen as an important stat as far as research goes, but I'd far rather focus on the ebb, flow, and varying proportions of BG values that lie behind it. But that's another post I'll probably never get around to writing...

Here's hoping for a peaceful, healthy, happy and significantly more stable 2021 for us all.

Posted by on Tuesday, 8 August 2017

Fiasp review, fun with 50:50, and the mystery of the missing insulin

I have been using NovoRapid for many of my 'pretending to be my pancreas' years. I had a brief dalliance with Humalog not long after we started writing this blog, but switched back to NovoRapid when I started with Artoo as my DSN had worries about accounts of Humalog crystallising in pump tubing.

One of the challenges with NovoRapid, as many users are keenly aware is that it's not very... well... rapid. NovoSluggish perhaps? NovoOhForGoodnessSakeGetAMoveOn!

When your blood glucose is stubbornly high and you dose a correction only to find it even higher an hour later it is very tempting to rage bolus it into submission with multiple additional units, only to find that you crash into low blood glucose hours later once they have all started acting together. I once wrote a post about speedboats and oil tankers outlining my frustrations around slow insulin action where everything else seems to act very fast indeed.

For those that don't know Fiasp (Faster Insulin Aspart) is the latest insulin from NovoNordisk. It is similar to NovoRapid, but has some additional ingredients that have improved the speed of onset. Official trial data shows a relatively modest improvement, but there has been much excitement in the DOC, and the early experiences shared seemed to suggest some people saw significant differences with faster action and a shorter duration.

I was keen to try Fiasp to see if I could do away with my reasonably lengthy pre-bolus at breakfast and lunch (taking insulin at least 30 minutes before beginning eating) and also to see if I could see improved/faster action of correction doses. This blog is my n=1 trial of 3 vials, I cannot say how Fiasp would work for you or anyone else, but this was what happened when I tried it.

But before we get started...
(jump to the Fiasp bit here if you're in a hurry, but you'll be missing out on some *sparkling* blogrambling)

The mystery of the missing insulin #1
When I spoke to my pump clinic about getting Fiasp they could not prescribe it because it was not yet on the hospital formulary. I had to get it from my GP who could use the PIP code to prescribe it directly. I planned to try it for 3-6 months to give me long enough to experiment with it and give it a decent go. I generally get 3 vials at a time when I order insulin. each u100 10ml insulin vial contains 1,000 units, which at my general Total Daily Dose of 30-35u should last me around a month each, more or less.

Except that they haven't.

Looking back, my insulin use has been pretty much as expected, but I used up those vials in 57 days not 90. And I am always careful to draw out every drop out of each vial, conscious of the huge privilege it is to live in a country where insulin is provided free for me by the NHS.

I had never realised before how much insulin prescribed to me goes unused. If I lived in the US with their absolutely horrendous price issues it would make a huge difference. Every set change for my insulin pump requires the tubing to be filled, and at the end of the site's life, that full tubing is discarded. I'm careful to only fill reservoirs with just enough insulin for their 3-day life, and have run them to all but empty more than once, but even then, there is a substantial measure of insulin left at the neck which you can't get to.

What this has showed me though, is that if planning a lengthy trip away, I would need at least a third more insulin than I might have guessed.

Oh and one more thing before we get going...

The mythical 50:50 split and other 'rules'
Immediately before switching - NovoRapid doing very well
I knew that changing the insulin I was using would most likely involve resetting a lot of things - ratios, factors and so on. So I decided (looking back this was probably not one of my brightest moments) that it would provide me with a useful opportunity to finally experiment with that mythical 50:50 split that some Healthcare Professionals seem quite keen on where exactly half your insulin is used for basal and half for meals. Along with the 500/100 'rules' that often get mentioned to me in clinic. I have always thought these 'rules' to be useful starting points - academically interesting, but no real substitute for systematic (and repeated) self-testing of basal insulin with fasting basal tests for example. Here was a chance to see how it worked for me.

So when I switched to Fiasp, I took an average of my Total Daily Dose (TDD) over the previous 30 days and split it exactly 50:50, then set a flat basal profile to spread that much insulin over the 24 hours. Apparently in most people with a functioning pancreas, the body uses half the insulin for food and half for background. Quite how they have worked this out is beyond me. And I've always thought, "Well surely, doesn't that depend on what you are eating??". But nevertheless the 50:50 thing still floats around and some HCPs raise eyebrows when your split is more 40% basal to 60% bolus as mine is.

Part of the reason why I half-thought this might be a useful experiment (apart from my own curiosity and thinly veiled desire to prove that it was nonsense and wouldn't work for me), was that I had read accounts by a few people who had tried Fiasp already that found it had a shorter action. By boosting my basal split to half of my TDD, I reasoned I might soften that out a little. Take less insulin with each meal, but still have some being fed-in continually in the background that I could dial down with a Temporary Basal Rate during exercise/activity.

Additionally I was wearing a CGM sensor during this period, and could watch what was going on, plus I had Smartguard to catch me overnight, just in case.

The first morning of my changing-absolutely-everything Fiasp trial showed a dramatic drop overnight - caught by Smartguard and low prevented, but enough to confirm my suspicions that a significant hike in overnight basal insulin would cause me problems going forward. Undeterred, and wanting to give the experiment more of a go I adjusted the pattern to shift some of the basal insulin into the daytime and keep the pattern at 50% of my TDD.

500 and 100 rules
The other half of my Great Big Reset experiment was to use the 500 and 100 'rules'. These are a suggestion of calculating your insulin:carbohydrate and correction factors using your TDD as a starting point:

1u of insulin covers: (500 / TDD) grams of carbohydrate
1u of insulin lowers BG by: (100 / TDD) mmol/L

The correction factor always works out very similar to the one I generally find works OK for me, but the meal ratio is always a bit of a surprise. More than once in clinic when the subject of hypoglycaemia has come up a calculator has been tapped and mentions made of what my ratio 'should be' according to the 500 rule - I often use 1:10 and 1:11, the 500 rule suggests 1:15. I've always been of the opinion that if my meal ratio were 50% out, I might have noticed, but this Brave New World was an opportunity to have a go and see what happened.

'500 Rule' boluses really struggling
After a couple of days I took stock. I had been experiencing a lot of high glucose alarms and had needed to dose several extra corrections to bring my levels back into range. Hilariously when I looked at the splits between basal and bolus I noticed that the extra corrections I had needed pushed me back almost exactly to 40:60 rather than 50:50. My diabetes can be extremely stubborn sometimes.

Additionally, I soon realised that the 500 'rule' was massively messing with my attempt to aim for 50:50. Even though I was using my TDD as a starting point, I simply do not eat enough carbohydrate most days for the 500 rule to generate half my TDD. I usually eat around 130-150g of carbohydrate per day. Don't get me wrong... I'm no sandal-wearing low carb evangelist. Sometimes I can eat 120g of carbs in a single meal - but on the whole, I find around 150g is all I need, and helps keep my BG a little more stable. The 500 rule seemed to assume I would be eating 250g of carbs a day. Which I can do, but carbier days are often the less predictable ones in my experience.

So I gradually began to tweak my basal profile and opted for more of a mid-point for meal ratios, and the experiment continued. I lasted around a week before I threw the towel in. I only hit the mythic 50:50 split on one or two days (about as many as I do using my own system to be honest). Most of the days with the 500-rule-ratios involved significant corrections due to rising levels, however quickly Fiasp may have been working. And more often than not these pushed my basal:bolus split back to where it normally sits.

Finally! The Fiasp part of the Fiasp Post
If you've waded through these ramblings so far (congratulations, some sort of perseverance medal is clearly in order) you will understand why I am choosing to pretty much ignore my first week's experience with Fiasp.

Looking back at that first week though, I will just briefly mention in passing that we were away on holiday and so there were a good few treats to test Fiasp's rapid action. I was also experimenting with not pre-bolusing for breakfast or lunch. Early results were promising once I had tweaked my ratios a little. Doses for other things, like white bread, ice cream, cake, beer did seem to be starting to act more rapidly, and where I'd misjudged things and was dosing for corrections they seemed to be starting to act within 25-30 minutes rather than my expected 60 minute wait with NovoRapid before I see much BG reduction.

I think it's fair to say that Fiasp had its work cut out because in the months before trying it, partly powered by the occasional CGM sensors I've been running this year, NovoRapid had been unusually cooperative. Many weeks with more than 80% of sensor readings in range and with almost no minutes below 4.0mmol/L.

Faster acting
After my slight false-start and once I had my ratios and basal back to more like where I would expect them to be I began to find my feet with Fiasp. During this period, here's what I found:
  • I did still need to pre-bolus, but only about half as much. Perhaps 15-20 minutes at breakfast and 10-15 minutes at lunch. Much more than that and I risked dipping low before the carbs kicked-in.
  • Corrections were acting faster, just as I hoped they would. This meant that my errors were resolved more quickly
  • Meals where I would not normally need to pre-bolus and where I'd expect reasonable results from an 'all up front' approach I actually needed to delay the meal insulin. Setting all or part of it as a square wave/dual wave/combo
  • Smartguard occasionally mangled these square and dual waves, cutting basal insulin and stopping the remaining bolus following a small dip in BG and just as the carbs began to hit, resulting in the dose only being delivered later on when I noticed what was happening. This was intensely frustrating.
  • The insulin action did seem to be shorter than NovoRapid for me, or at least the way that Fiasp makes more of the dose available sooner meant that the tail was less pronounced and I reduced my duration of insulin action to better reflect 'insulin on board'
  • Breakfast was my biggest challenge. Lower carb weekday ones (15-20g carbs) were relatively OK, but bigger weekend ones (45-50g carbs) were a nightmare. At some points in the year I can find I have to add an extra mini-bolus to account for my liver dumping glucose when I crawl out from under the duvet (even though my basal pattern always kicks-up at this time), but even that tried and tested strategy didn't keep me out of the teens after breakfast at the weekends. In the end I used a surprisingly strong bolus ratio that scaled the doses upwards where I was eating more.
Fiasp performing pretty well at 3-4 weeks in.
Finding the Fiasp sweet spot
There was definitely a point, when I'd been using Fiasp for about 3-4 weeks where I began to see distinct potential. There were still some horrendous numbers to be found, but there were some great successes too. For example, a Tapas meal out one Sunday with delicious breads, patatas bravas, beers and all sorts of incalcucables that was bolused late, in a series of guesses and to correct my earlier underestimates of carbiness where I could actively see Fiasp's faster action helping me out.

It was also at this time that my results around breakfast greatly improved, which helped a lot in improving my time-in-range.

What it made me realise, I suppose, was that after something like 15 years of using NovoRapid I had memorised a lot of 'exceptions to the rules'. Little tricks and strategies that I use, almost without thinking, to work around NR's particular activity profile and my individual BG response to different foods. When switching to Fiasp, I was needing to re-invent a lot of these, and discover a whole lot of new ones. If the switch was to become permanent, it would take time to build up this knowledge.
Things improving around breakfast time with Fiasp

Increasing resistance and the mystery of the missing insulin #2
Unfortunately my successes were fairly short-lived. I can see the Standard Deviation (how spread apart my BG results were) taking a leap upwards after about 10 days of beginning to feel I was making progress. During this phase of my Fiasp experiment my basal and bolus requirements seemed to be heading inexorably upwards once again (they had kicked upward after a couple of weeks, but I'd seen that happening to others and didn't stress about it too much). At the same time I was finding my earlier shorter pre-boluses less and less effective, and had more or less reverted to exactly the timings I would use with NovoRapid. Additionally, I no longer needed to dual or square wave those well known 'all up front' meals as I had in the first few weeks.

Even more perplexingly, rather than acting more rapidly, sometimes my corrections of high BG values seemed to have no effect at all. I would be watching a sensor trace waiting for a high or rising BG to be corrected and nothing would happen. I began to throw in 2u and 3u speculative 'turnaround' corrections to try to halt a rising BG only to see it continue to rise, and where I was expecting to have to mop-up the excess insulin with carbs later, the dose seemed largely to disappear entirely.

As an example, in the image you can see my BG rising after an early evening meal. The blue dots along the bottom represent corrections. The first, before 7pm was in response to an 'alert before high' which indicated I would be rising to 11mmol/L within 30 minutes. I gave a small correction (0.7u) which aimed to take the edge off the rising BG. Over an hour later, not only had the remainder of the meal bolus not reduced my BG, but the additional correction was not doing much either. By 8.20pm or so I was getting a little frustrated and bolused 3u planning to watch and wait -  mopping up with some tasty carbs once my BG had begun to drop. In the early days of Fiasp I would have expected even a modest correction to begin to lower BG within 30-45 minutes (unless immediately after eating), but over the next hour my BG continued to rise. The two corrections already on board almost doubling my meal dose. A further small correction at around 9.20pm did finally provide some BG lowering effect and I went to bed mid-range after a small snack. For anyone wondering about the condition of the infusion set - it returned to much more expected behaviour overnight and the following morning. But it was odd events such as this that rather cast a shadow on my Fiasp experiments. I began to opt for 3u and 2u over-corrections fairly often.

I was also increasingly aware of a stinging sensation at the infusion site. Not always, and sometimes stronger than others. But many infusion sites were noticeably tender to the touch.

Losing faith with Fiasp. Averages and SD rising.
Calling it a day
It was about this point where I decided that Fiasp was not going to work for me. I was nearing the end of the third vial of Fiasp and needed to put my repeat prescripton request in to restock. I decided to return to NovoRapid.

I am sure I could have made it work given enough time, but I was losing trust with it and finding it not altogether reliable or predictable. This was relatively manageable when I was wearing a CGM sensor to keep track of where doses were not behaving as expected, but I generally only use sensors occasionally and I really need an insulin that I can trust while I'm not able to watch it like a hawk.

Ultimately, I had wanted to try Fiasp to reduce or remove the need for pre-boluses, and to improve the speed of action of corrections. I had seen some evidence of these early on, but not for several weeks. And those positive attributes had apparently been replaced by a less than reliable action.

I am quite disappointed if I am honest. I continue to see lots of accounts of people getting on really well with Fiasp, enjoying lightning speed and seeing significantly improved post-meal numbers. I have also seen other accounts very similar to my experience though. So it seems that Fiasp may be an insulin that just does not work well for some people.

But for me - despite all its faults, NovoRapid has brought an immediate relief and return to significantly better results. Well... for the time being at least!


Posted by on Monday, 15 May 2017

Medtronic Guardian Connect Review - iPhone CGM in the cloud

Guardian Connect on iPhone, Guardian 2 on MM640G
and Contour Next Link 2.4
As some of you may know I've been lucky enough to be wearing Medtronic's new box of CGM tricks recently, and with nearly 4 weeks' wear under my belt and a few more days to go, it seems about time to post my thoughts about this new addition to the list of CGM options.

Ground rules
As I have been reflecting on my time using the Guardian Connect, a few things have stood out to me from the start. The first is that this is now the third continuous sensor system that I have tried. My first experience was Abbott's Libre flash glucose monitor (not strictly a CGM) and later, the MiniMed 640G sensor-augmented pump system which I trialled for 9 weeks in 2015. I mention this, because I think it has a significant effect on how I have responded to the Medtronic Guardian Connect. I am now no longer comparing 'no continuous data' to 'continuous data' which is, in itself, a huge change. Essentially you can take for granted that I am enjoying all the 'usual' benefits of access to continuous data - the ability to glance at your glucose level whenever you want to; overnight basal test type traces every morning, and trend and 'direction of travel' indicators. So what you get here is more me comparing the tiny details in user experience between the various systems, rather than being swept along by the benefits of CGM itself. I'm not sure if that makes this more or less helpful for anyone reading... but there it is.

Initial bewilderment
I don't know if you know anything about the Guardian Connect as you start reading this, or any other Medtronic diabetes technology for that matter - I mean why would you? But me... I'm on the inside, and that perhaps gave me certain expectations. I first chose a Medtronic Paradigm Veo which tantalisingly offered a 'low glucose suspend' if paired with the sensors that I never quite managed to afford. When I subsequently trialled the MM640G with it's souped-up 'predictive low glucose suspend' I think it's fair to say that for me, the results were extraordinary. Finally a piece of diabetes technology was actually proactively helping me out - dodging hypos automatically while I was blissfully unaware. So when I was first invited to trial the Guardian Connect I assumed that, of course, it would integrate with Medtronic pumps, SmartGuard and all the rest... Well... it doesn't.

So... CGM on iPhone... CGM in the cloud... sounds great! But what do you mean it doesn't link with SmartGuard? - I mean, wait... what?!
What I knew from the outset, was that the Medtronic Guardian Connect was a CGM that displayed sensor glucose readings on your iPhone, which sounds cool. And that it was Medtronic's 'CGM in the cloud' solution, which has very much been the buzzy new thing to have for a year or two. But I confess it completely threw me that this new CGM would not also communicate with my pump.

A new product line that explicitly doesn't offer the market-leading benefits of other devices in the same stable, while simultaneously offering all that trendy cloud-share-ness. Medtronic giveth, and they taketh away. Of course, Medtronic are keen to point out that the Guardian Connect was always designed as a standalone CGM (Medtronic have had a standalone Guardian CGM line for as long as I can remember). They say that this technology is intended for users of other pump brands, or people on multiple daily injections (MDI). Well... maybe. But I still find myself wondering whether a company would take this sort of decision if we were not living in a global marketplace with such complex approval mechanisms and timelines in different locations.

In a way I can sort of understand it from a technical perspective - my MM640G communicates on a completely different frequency to the bluetooth on my iPhone, so a transmitter would have to be able to send information to both devices. Would that increase transmitter size? I don't know - to be honest, I'm not really sure I care. All I know was that finding out that all the Guardian Connect iPhone-displaying-cloud-sharing juiciness came at the expense of SmartGuard was a real kicker.

The disappointment was particularly sharp when I discovered that people in the US have access to MiniMed Connect, which does link a MM530G, essentially a Veo with low glucose suspend, and transmits CGM to an app on iPhone or Android. Apparently MiniMed Connect is soon promised for the MM670G too - a newer pump than mine and not available in the UK. But all things? Approved in all markets? Available in all countries? Apparently not.

CGM displayed on your iPhone? Brilliant!
Having said all that, the idea of getting your sensor glucose sent to your iPhone is very appealing. I have very limited pocket space, and having to avoid scouring my phone screen to oblivion I need to keep keys and loose change in one pocket and my phone in another. So when using a Libre, with its separate reader, I have to squish reader and phone in the same pocket, and keep the reader in a little fluffy sock to keep them apart. Yes, you are right I am *such* a nerd. In short, having to carry a separate reader is a bit of a bind and the idea that I can use something I always carry with me anyway is hugely appealing.

Users of robot, rather than fruit-based smartphones may be wondering at this point whether Guardian Connect is available for Android? Well, at the time of writing, it isn't. And unfortunately I have no idea when, or if, an Android release might be available.

CGM in the cloud
The conspicuously 'on-trend' facility of the Guardian Connect is the way that it links to your Carelink account and can use a small slice of your phone's data connectivity to seamlessly upload your CGM data in the background. This gives you the opportunity of sharing your live CGM data with, for example, a partner, family member or housemate. This facility is particularly welcomed by parents of children with diabetes, who are able to keep an eye on things while their youngsters enjoy freedom to roam. Additionally Carelink allows you to set up text alerts, which will send an emergency message to a number or set of numbers if you do not respond to a low glucose alert. A potential lifesaver.

I think it is fair to say that personally I am not keen on Medtronic's Carelink platform. Particularly in its difficult current phase which is fraught with warnings of incompatibility if you dare to use current and up-to-date software. Medtronic promise that they are looking into upgrading their aging software, but evidence of progress or timeline remains frustratingly absent, aside from the recent release of Carelink Pro reports for everyone. The upshot of this lack of updatedness is that if you attempt to log-in to Carelink via iPhone you are greeted with a warning screen. However once you clear the warning, the live CGM data shows without problem. This easy access to sharing sensor glucose information has potentially powerful safety implications and would be a major encouragement, much as it is with Dexcom's Share, and the more homespun Nightscout options.

Getting set up
Before getting up close and personal with the new CGM technology, the first order of business was to download the Medtronic Guardian app from the App Store and hook it into my Medtronic Carelink account. For me, the next phase glamorously took place at the Diabeter clinic in Rotterdam, and involved pairing the Guardian Connect transmitter via Bluetooth to my iPhone. Screens in the Guardian app walked you through the pairing process, and an internet connection was required for the set-up. Once the ground work had been done it was simply a matter of inserting the Enlite sensor and waiting around 2 hours for the sensor to start-up. The Guardian Connect uses the same Enlite sensors as the MM640G system, but uses a completely different transmitter in order to communicate with your iPhone, iPad or iPod Touch.

Calibration 
Once the sensor has warmed-up you are prompted for a fingerstick calibration, which you enter into the app by pressing the blood-droplet 'calibration marker' top-right. This then shows a green circle around it which begins to count down, handily indicating the approximate amount of time before the next calibration is due. The precise timing being shown on the calibration entry screen itself. The calibration follows the familiar Enlite pattern of 2-6-12 hours after insertion and then approximately 12 hourly after that. The Guardian Connect also has the ability to request an additional calibration if it worries that things might be drifting slightly. My habit with Medtronic CGM has been to calibrate immediately before most meals (as long as they are not expected to be horrendously spiky ones). I find that 4 calibrations a day usually keeps an Enlite tracking very well for me. The usual guidance on calibration applies here - you should choose a time where, ideally, BG is within your target range, has been stable for 30 minutes or more and is expected to remain stable for the next 30 minutes. Avoiding calibrating when the Guardian app is showing up or down arrows really helps to keep the calibrations true. One nice thing about calibrations with Guardian Connect is that they are significantly faster than when I have used Enlite sensors with my pump. Connect calibrations are done and dusted within 5 minutes, while it can take 10-15 for my pump to finish calibrating.

Once or twice over my time with the Guardian Connect I have been prompted for an additional calibration overnight, which was initially confusing as I knew I had calibrated at around 11pm so should have been OK until morning. I suspect these were down to a less than ideal calibration earlier, eg one with BG moving or above target range.

A note for non-CGM users 
It is probably worth noting at this point for anyone reading who is considering using CGM for the first time the whole 'accuracy' question. People spend endless hours debating relative accuracies with CGM devices, and stressing or worrying if fingerstick and BG results are not identical all the time. In many ways, this is largely a waste of effort because a continuous sensor and plasma-calibrated blood glucose test strip are measuring completely different things - so they will never, can never show the same results all the time. It takes a while for glucose concentration in the fluid between tissue cells (that sensors measure) to come into line with capillary blood glucose. The differences are most noticeable when blood glucose is changing rapidly, and I particularly notice the lag when waiting for sensor glucose to show recovery after a dip into hypoglycaemia where the sensor may be 10 minutes or more behind 'now'. So you are well advised to decide to be fairly relaxed about any differences you see - providing, of course, that in general the information is within usable parameters.

For interest I am intending to give a suggestion of how I have found the tracking of Enlite sensors matches with fingerstick BG by taking a week of paired calibration readings. I've not got time to do that today, but I will add it here as soon as I can. My general feeling is that tracking between Enlites and fingersticks with the Guardian Connect is really very good indeed. And I trust it pretty much all the time. It's interesting to note how my frequency of fingerstick testing has fallen away while wearing sensors. Many days only checking fingersticks before meals, before bed, and before driving.

Update: Calibration and tracking vs Contour Next Link 2.4 
As promised I am editing this post to include some pairs of results between Enlite sensors on the Guardian Connect and my fingerstick BG meter (the Contour Next Link 2.4 USB that connects to my pump). Out of interest I have also done a comparison between the 'calibration' pairs for one of the sensors I have been using with my MM640G using the Guardian 2 transmitter - just because I was curious to see if there was any difference. Essentially I have looked at all the fingerstick BGs over the official 6 day life of the sensor that I used for calibration and compared them to the sensor glucose reading at the time. I should stress that this is not very scientific, and mostly for my own interest. The data set is pretty small (29 pairs for the Guardian Connect and 26 pairs for the MM640G). For what they are worth, here they are:

Medtronic Guardian Connect / Enlite results compared to Contour Next Link BG meter
BG meterSensorAvg +/- %
(against BG meter reading)
Avg +/- mmol/L
(against BG meter reading)
Average8.4mmol/L8.3mmol/L7.8%0.6
SD2.82.55.7%0.4
Distribution of readings
Number of readings where sensor higher1138%
Number of readings where sensor lower1655%
Number of readings equal310%
Number of readings within 0.5mmol/L1345%

Medtronic MM640G / Guardian 2 / Enlite results compared to Contour Next Link BG meter
BG meterSensorAvg +/- %
(against BG meter reading)
Avg +/- mmol/L
(against BG meter reading)
Average7.2mmol/L7.2mmol/L7.7%0.6
SD1.51.15.7%0.5
Distribution of readings
Number of readings where sensor higher1246%
Number of readings where sensor lower1142%
Number of readings equal415%
Number of readings within 0.5mmol/L1350%

My feeling is that these results are pretty much exactly the same between the two systems, which is reassuring, especially given the more varied results I was having on the days with the Guardian Connect with a higher average and wider SD (range of results). The MARD of less than 8% difference is above the expected performance of these sensors - I have always thought I must have lucky 'body chemistry' or whatever it is that means the sensors work better for some people than others. Effectively, it shows me that most of the time either of these systems will give me a result somewhere around 0.2-1.0mmol/L different from a fingerstick BG measurement (with potentially larger differences if my BG is moving rapidly, obviously). Around half the time, where my BG is just pottering along, sensor glucose and BG fingerstick are going to be less than 0.5mmol/L apart. And that is a level of accuracy I find easy to trust, and extremely useful in informing my diabetes management day to day.


Inside the app - traces, alerts and arrows
As a full CGM, the Guardian Connect offers both a rolling view of sensor glucose and audible/vibrate alerts if sensor glucose is, or is predicted to be, outside of a range you set. Today's sensor values are plotted as a graph and are viewable in 3hr, 6hr, 12hr and 24hr versions which each allow you to swipe back through previous time periods. Holding a finger over the graph reveals a scrolling pop-up of the value at that time. Additionally you can open the 'Now' menu to look back through previous day's sensor data.

Current sensor glucose is displayed above the graph, along with the menu and calibration icons. Where sensor glucose is changing more rapidly single, double or triple up or down arrows appear alongside the current sensor glucose reading.

Helpfully, when the sensor is coming close to expiry, or is running short of battery, you are alerted by icons on the main screen. Alternatively, you can always view the current details by looking in the menu screen.

The Guardian app also allows you to log insulin doses, carbs, blood glucose readings, activity or to make notes. The interface for adding and viewing each of these is pleasingly slick, but unfortunately you are required to log each value on a separate screen which would make regular use of them rather tiresome so I can't really see myself manually logging much additional detail using the app. The ability to add notes to provide context to what you are doing could be very handy though.

I was really pleased at the configurability of the alerts with the Connect. You can set both high and low alerts, along with additional alerts which are triggered anything from 10 minutes to 1 hour before your hard limit is expected to be reached if current sensor glucose trajectory continues. You can also set alerts where glucose is falling or rising particularly quickly. Snooze time allows you to customise how frequently you will be reminded of an alert condition - high and rise alert reminders can be set between 5 minutes and 3 hours while low and fall alerts can be set between 5 minutes and 1 hour. This probably all sounds needlessly confusing and granular in detail, but one of the challenges with CGM is to get good usable prompts without feeling nagged all the time, which makes the ability to precisely tailor both the mixture of alerts and their nag-ability really important.

You are also able to set an optional alert as a reminder that calibration is coming close to being due (rushing out of the house with no BG meter when a calibration comes due could make sensor glucose unavailable).

Not only that, but any and all of these alerts can be silenced at once with a single press on the iPhone's 'Control Centre' - more on that a little later.

Widget and app frustrations
Enabling Guardian Connect in the Notification centre can give you access to both alerts and a sensor glucose 'widget' on your phone's Lock Screen. Inexplicably though, the widget for a mmol/L Guardian Connect displays sensor glucose in mg/dl in the Lock Screen widget. Thankfully, as an app, this *should* be relatively easy for Medtronic to fix, but it still looks a little messy. Until the fix, users will just have to fall back on the, 'divide by 10, divide by 2, add 10%' mental acrobatics - unless their 18x table is reeeeeally good. As an example... 250 divide by 10 is 25. Half of 25 is 12.5 and then add 10% which makes 250mg/dl roughly 13.7mmol/L. Inside the app, alert states are shown by use of a coloured overlay panel.

Another frustration I had with the app, for all its smooth animation and solid build, was the total lack of any data analysis. I'm not sure whether this is something Medtronic have slated to add in future releases, but it seemed to me to be a significant missed opportunity not to have some sort of 7, 14, 30, 90 day sensor data overviews and number crunching. Or better still a pinch of Ambulatory Glucose Profiling to help make sense of that avalanche of data.

Enough with the interminable detail already - tell us what it was like to actually use!
Yes, sorry about that. Where were we...

Well... it's interesting. And actually I have been rather surprised by the experience. I think the only way to get my head around it is to list it as a series of pros and cons.

Pro - Less to carry, and very unobtrusive
Not having to carry an extra, separate reader has major benefits in terms of pocket space. We are used to carrying phones. We are used to glancing at them. No one would have any idea that you were interacting with your diabetes, even if you respond to or check an alert. Because that is what people do all the time in the modern world. There are a variety of tones used by the app, which indicate different things going on even before you get the phone out of your pocket. I kinda wish they had made the high and low alert tones slightly more varied. They do step up and down, but there is only around a semitone between the beginning and end and a quarter tone in between those, which all happens very rapidly. Occasionally I have heard the tone, but been unable to work out whether it was rising or falling. Of course it's not a real problem as it's only a glance at the screen to confirm - but I would have preferred that fraction of a second heads-up especially in circumstances where I might not be able to get my phone out for a minute or two.

Con - Now your phone is something else
Using the Guardian Connect has required me to make some adjustments in the way I use my phone - because now it is also my CGM receiver. I generally have my phone on silent, but I soon found that the single 'buzz' vibration alerts were too easy to miss, so I needed to put my phone's sounds on. Remember the single control centre command I mentioned to (helpfully) silence all CGM alerts if ever you needed to? It's the iPhone's 'Do not disturb' setting, which I have had running automatically overnight for several years. This prevented alerts sounding for ovenight hypoglycaemia, so I've had to de-activate its schedule and now activate it manually if I need to be notification-free for a time.


Pro - Phone battery life still reasonable
I am used to getting decent battery life out of my iPhones. Something like 3 days from a single charge - I suspect this makes me something of a rarity. I don't have a lot of push data notifications going on, and I deliberately restrict many of the usual battery hogs like background app refresh and screen brightness. I was a little concerned that the drip feed of continual data might suck all the life out of my battery, but while Guardian Connect has added a not insignificant demand on battery life I am still getting at least a full 2 days out of a single charge.

Con - battery charging
Of course, the flip side is that if you do run out of battery, it's no longer just your Twitter feed that you are missing - its your CGM and alerts too. And if your phone needs charging during the day, for all the time it's connected to the power socket you need to stay within about 9 feet of it to receive CGM alerts. This makes overnight phone charging a good basic approach.

Pro - gap filling
There have been times when my own peculiar charge cycle has got the better of me, and I've had to leave my phone charging on the side while I leave the room (or even the house) to do whatever. The neat trick of the Guardian Connect is that it stores several hours of data in the sensor, so that when you finally reconnect app and sensor the gaps are automatically filled in and your data remains intact. You don't get the missing alerts, of course. But at least you can look back over what has been going on while you've been away from your phone.

Con - Alert volume
Most of the time, when inside, the alerts are plenty loud enough. But the world is a busy, noisy place, and all too easily when walking outside I have missed both noise and vibrate alert. As a consequence I have tended to use the Guardian Connect a little like a Libre when out and about. Making sure I check it relatively frequently and not assuming the audible alerts would be able to cut through the hubbub. Sadly there's no way of making only the Connect alerts loud and leaving all your others at a quieter level, so it's a bit 'all or nothing'. I suppose as a fallback you could set a shorter alert snooze time so that you would get more repeated reminders of missed alerts.

Conclusions
I've not run any kind of analysis of BG numbers or hypoglycaemia frequency between Libre, MM640G/Smartguard and fingerstick-only as part of this review - quite frankly if you've made it this far I think you deserve a medal! I may try to find time to take a look at that in coming weeks with the data that are now safely stored in Carelink.

There is an awful lot to like about the Medtronic Guardian Connect. Despite my initial bewilderment, as a standalone product I think it sits very well among the current market and there is much to recommend it.

Medtronic get a bit twitchy at the idea of people who are trialling their kit restarting sensors, but having self-funded the same Enlites that this system uses since January I have found that I can get 12-14 days out of those with little if any apparent loss of performance. For anyone considering self-funding, the ability to restart to extend sensor life can be a make or break factor and I have no reason to believe that the Guardian Connect would behave differently to the Enlite's I've been using with my MM640G. Having said that I may just have lucky body-chemistry as I know from other user-groups that some people struggle to get more than 6 days out of an Enlite - so as ever YDMV.

My few weeks with the Medtronic Guardian Connect have given me very solid CGM performance, brilliantly flexible and tailorable alerts and while lacking the automation of Smartguard I get the feeling that the Guardian Connect has really helped me to keep my BGs in range, with very few hypos, and hardly any highs.

I've enjoyed using the system, though for a number of reasons I don't think it's one for me long-term.  I hope you've found this review interesting, please share your thoughts below.

Disclaimer: Medtronic offered me a trial of the Guardian Connect on loan with enough sensors to last 30 days. I have not been asked to write this or any other post about it, and have tried to accurately portray my likes and dislikes of the system. If I had thought it was utter rubbish I would have said so.

Posted by on Saturday, 12 September 2015

64 Days with the Medtronic 640G: Ep 9 Review - the best and worst of the MM640G

Well, this is it. The last of my posts covering my time with the Medtronic MiniMed 640G. Thank you so much for bearing with me over the last few months. Normal wittering will be resumed shortly. However, as seems to be the way of things with blockbuster franchises (HA!) I have split this last episode into two parts. Part (i) covers all the little niggles and irritations I had while using the MM640G, while part (ii) looks at the things I loved, and reviews my results including reductions (if any) in hypoglycaemia and an HbA1c I had done at the end of my time using the pump. HbA1c is the test which measures how much of the glucose in your blood stream has stuck to red blood cells. It is often used as a measure of your likelihood of developing the long term complications of diabetes.

For those who really can't bear wading through all those minutes of video I will summarise the results below. The video gives a lot more detail though, and features a fluffy bunny. What's not to like?!

When it comes to the things I really liked/disliked about the MM640G you will need to bear in mind that I am comparing to a MiniMed Veo. All of the really good stuff about pumps generally - precise basal patterns, advanced dual and square wave bolus options for tricky meals, ease of use, bolus calculator, temporary basal rates, precision of doses and correction factors, blah, blah, blah... are already assumed to be present and correct. Some of the things I loved about the MM640G are precisely because they fixed annoyances I found with the Veo. But more on that later. First:

The worst of the Medtronic MiniMed 640G

Those who have read any of my reviews before will know that I can get unreasonably irritated by the slightest things. It will come as no surprise then, that while I generally loved the MM640G both with and without sensors, there were a few things about it that drove me nuts.

  1. Pump lock
    After a few minutes the pump automatically locks and most interactions require you to play an annoying 'press the right button' game. This is no good if you are in a hurry, and is not an option that can be turned off.
  2. Change of orientation
    It's now 'portrait' not 'landscape'. As someone who wears an insulin pump on my belt this is a bit awkward.
  3. Belt clip
    As I mentioned in the first of these videos, the new belt clip is hopelessly flippy-floppy and needs a much firmer spring. The inbuilt tool for opening battery cap is cool though.
  4. No small versions
    Medtronic have now abandoned plans to produce a smaller version of the pump. All MM640Gs will now have the little sticky-up bit to accept the larger reservoirs. The smaller reservoirs can still be used, but at present, with approximately 35u/day usage, the 'how full is my reservoir' icon on my status bar is pretty much permanently red.
  5. Sensor overtape irritation
    The glue used on the sensor overtapes (and also the little patch that holds the sensor down initially) caused a red rash to appear after a couple of days of wear. Initially it was only toward the end of a sensor but in the end it began pretty much at day 2. I used an alternative dressing, but even that was pretty itchy. Weird - because I don't usually react to adhesives at all.
  6. Sensor swap delays
    From start to finish swapping a sensor takes around 3 hours to begin providing new continuous data. That's a looooooong time!
  7. Occasional sensor lag
    Mostly I found the sensor accuracy was brilliant. But sometimes, particularly if I treated a low to try to fix a below target BG reading, the sensor was a little slow in responding (perhaps 30 minutes behind reality). Additionally calibrations by BG meter do not necessarily reach up to match sensor glucose and BG fingerstick value, but often end up with some odd half-way house. If the sensor glucose value had drifted a little there were even occasions where calibration triggered an 'alert before high' which was doubly annoying.
  8. Sensor Glucose Review
    The one-day graphs which allow you to flick back through previous days' results show no indication of SmartGuard interactions or insulin doses. Makes them about 10% as useful as they could have been.
  9. Home screen without sensors
    For no apparent reason, the icons in the status bar do not align neatly when using the MM640G without sensors. There's a gap where one of the sensor icons(!) would go, which makes it look untidy and poorly considered. The enormous dotted line 'we have no BG information to show you' panel where recent meter BG readings go (when not using sensors) also irritated me more than strictly necessary. Just doesn't feel like the visual look of the home screen for most UK users, who will be using the MM640G without sensors, was given enough finesse.

Watch the video

The grumbles, gripes, and irritations - everyone will have their own, I'm sure.




The best of the Medtronic MiniMed 640G

Whether you use the MM640G with sensors or not there is a LOT to like about it. There are all sorts of little, pleasing improvements in the interface and options that make a massive difference. Add the wizardry of SmartGuard into the mix and things are taken to another level - but even without there are lots of tasty treats for non-sensor users.

  1. Setting basals and temp basals
    There are now up to five basal patterns on the MM640G, and brilliantly you can copy entire patterns from one 'slot' to another to experiment with and then switch back if you need to later. The patterns also come with helpful names to keep track of which are which: Work Day, Day Off, Sick Day, Pattern 1, Pattern 2. Which pattern is set is not marked on the home screen, but thankfully setting any of them does not cause the 'alert circle' to appear like it did on the Veo.

    Temp basals can now be set in 15 minute increments for more precision and alter up and down by 5% at a time making them much quicker and less fiddly to set.
  2. No TBR 'chime'
    Setting a Temporary Basal Rate no longer causes the pump to issue a useless wittery alert tone every hour, which means you can ACTUALLY USE THEM OVERNIGHT! In even better news - the end of a TBR is now indicated by a single beep. Brilliant!
  3. Different Alert Tones
    There are now a series of different alert tones to indicate different things. There were a few on the Veo, but so many overlapped with either 'pip-pip-pip' or 'naah-naah-naah' that I find it much easier to work out what is going on on the MM640G without having to check the pump for 'information' alerts and being alerted (ha!) to things that actually require action. The ability to increase volume has also significantly improved.
  4. No lockout during bolus delivery
    It is possible on the MM640G to do rather more things during the time while a reasonable sized bolus is being delivered - for example you can set a TBR. The Veo made you wait until the bolus had finished before allowing you to do anything (other than stop the bolus!). This meant I could group my pump interactions together and then get on with life, rather than having to wait around tutting.
  5. Screen visibility in sunlight
    Really, really good - especially compared to some other colour-screen diabetes gadgetry I have tried. Not perfect from every angle, but really easy to turn a little and see very clearly even in direct sunlight.
  6. Remote boluses from BG meter
    Not a full remote control with bolus wizard, but a really useful standby when digging your pump out from within clothing is impractical or inconvenient.
  7. Waterproof
    Now rated as IPX8 - up to 12 feet of water for up to 24 hours.
  8. SmartGuard - overnight hypoglycaemia
    Unsurprising if you have watched my Overnight Hypoglycaemia post, but SmartGuard overnight for me was a real stand-out winner. No readings at all for 9 weeks below 3.5mmol/L overnight, and hardly any below 4.0mmol/L. Some nights almost no basal insulin required, and others requiring my more 'usual' 6-7 units at night. Looking at the results it's hardly surprising I had so many problems and so much Severe Hypoglycaemia during my years on Lantus!
  9. SmartGuard - results overall
    When compared to averaged results from 10 weeks of Libre sensors (the only other 24 hour data I have) time in hypoglycaemia fell by 90% during my 9 weeks with the MiniMed 640G. At the same time my overall levels, as measured by HbA1c fell by 0.3%. And all this with less effort and very little 'alarm fatigue'.

Watch the video

Improvements to the pump (with and without sensors) and the all important results.



Conclusion

It has been a great privilege to experience the MM640G system, and for me the results were spectacularly good. The comparison with Libre data is an interesting one, particularly where hypoglycaemia is concerned. Times wearing a Libre sensor were previously my 'best ever' results-wise. The ability to spot hypos coming during the day and try to head them off (I generally scan a Libre sensor something like 30-40 times a day), plus the ability to spot low levels overnight and make hurried basal rate changes meant that I generally had fewer hypos on a Libre than I would normally. And yet when compared to these data, the MM640G system reduced my time spent in hypoglycaemia by 90%. To be clear, that means that for every 10 minutes I spent below 4.0mmol/L trying my very hardest with a Libre sensor, I would spend only one minute when using SmartGuard. That and my HbA1c dropped over the same period from 6.3% to 6.0%. 0.3% - it's not a huge margin, but those fractions are pretty tricky to shave off once you get down below 7.0 in my experience.

My only hint of melancholy about the whole experience is, of course, the eye-watering cost of full-time sensor coverage (approx £3,500 per year inc transmitter). It's not something we as a family can afford, and full time CGM on the NHS is reserved for those who really need it most - and rightly so.

It feels a little like being given a chance to live in a multi-million pound mansion and drive an Aston Martin for a few weeks to see how I like it. I may think it's brilliant - but the reality is that it's not really an option that is really open to me long-term.

I have a pump clinic coming up in a week or two and will see what they say about the results - particularly my unpredictable and occasionally lengthy periods spent below 4.0 overnight. These do nothing to help my efforts to keep my Imparired Awareness of Hypoglycaemia under control. I may ask about the possibility of part-time sensor coverage. Even a few months in a year would make a massive difference (as long as the transmitter continued to function, of course).

My Veo is nearing the end of its warranty period, so I am looking to the future. I have some thinking and some sums to do after this experience - depending on what my clinic say.

Final verdict (with sensors and SmartGuard): 5/5
Final verdict (without sensors): 4/5
Final verdict (considering self-funding sensors): 4/5*

* because of Dexcom's more 'stretchable' reputation when it comes to sensor life

Disclaimer: I was offered a trial of the Medtronic MiniMed 640G system for 64 Days with full sensor coverage so that I could share my opinion and experience good or bad. I was not paid to write this post, and if I had thought the pump was terrible I would have written that. I was encouraged (not required) to post video blogs about my experience, but Medtronic did not have any control over what I posted.

Posted by on Wednesday, 26 August 2015

New NICE Guidelines for Type 1 Diabetes Published (at last!)

As some of you may know, over the last three years (THREE YEARS??!?) I have been working with a wonderful group of fiercely clever and passionate people as one of two 'patient representatives' on the NICE 'Guideline Development Group' which was revising and updating the NICE Guidelines for type 1 diabetes in adults. Expert consultants, eminent physicians, nurses, pharmacists, GPs, educators, editors, along with a host of other specialists including researchers and health economists who gathered and organised an almost unimaginable quantity of research data for the group to filter through and consider.

It has been a huge privilege to work with them all, not least Professor Amiel, the chair of the group, who is a complete inspiration and quite the nicest person you could meet. We have not been permitted to mention anything much connected with the discussions until publication, but at last, today, the guideline launches here: ‘Type 1 diabetes in adults: diagnosis and management'.

Hooray!

If you have been living in a cave for the last 16 years and have never heard of the National Institute for Health and Care Excellence (NICE), they are an independent body working as part of the Department of Health who publish guidance on all manner of healthcare topics which aims to set the 'gold standard' of evidence-based care, balancing clinical outcomes, patient preference and quality of life against the cold hard reality of NHS budgets (ie Yes! You can have something expensive... but only if published research shows it's reeeeeally good for most people).

As a patient, I *love* the fact that I can have a weighty, official, authoritative document that describes what has been shown to be the very best in diabetes care. It gives me something to consult to measure my own experience in clinic, and the right kind of pointy questions to ask if I think I should be getting something that isn't being offered. Plus if I think something should be available that isn't, the documentation is so comprehensive that (if I wanted to) I can dig down into the 'linking evidence to recommendations' section to unpick the reseach and discussions that underpinned the recommendations.

NICE seems to get a hard time in the press off and on (either for denying treatment, or for recommending it) and is frequently accused of bias or an almost corrupt collusion with the pharmaceutical industry. I have to say this could not be further from my experience of the guideline development process. Each meeting included a new declaration of 'conflict of interest' and anyone with a conflict, financial or otherwise, however minor, was not permitted to contribute to the discussion or was asked to leave the meeting entirely.

I am very proud to have been part of the process, and believe that this updated guideline, if fully implemented has has enormous potential to improve the lives of adults living with type 1 diabetes in the UK.

Here are a few things I'm really pleased made it into the final version:

Structured education
Offer all adults with type 1 diabetes a structured education programme of proven benefit, for example the DAFNE (dose-adjustment for normal eating) programme. Offer this programme 6–12 months after diagnosis.

If a structured education programme has not been undertaken by an adult with type 1 diabetes by 12 months after diagnosis, offer it at any time that is clinically appropriate and suitable for the person, regardless of duration of type 1 diabetes.
My feelings about the lack of structured education formed no small part of my journey toward joining this NICE committee. Carb counting, dose adjustment, correction factors, basal testing, guidance about exercise, alcohol and sick day rules. How can people be expected to make a decent go at managing their type 1 diabetes without these skills? And yet the number of people who have ever attended such a course is pitifully small. Unless I'm mis-remembering it's something like 6.5%. Let's hope that during the life of this guideline that changes significantly.

Access to test strips
Support adults with type 1 diabetes to test at least 4 times a day, and up to 10 times a day if any of the following apply:
  • the desired target for blood glucose control, measured by HbA1c level (see recommendation 1.6.6), is not achieved
  • the frequency of hypoglycaemic episodes increases
  • there is a legal requirement to do so (such as before driving, in line with the Driver and Vehicle Licensing Agency [DVLA] At a glance guide to the current medical standards of fitness to drive)
  • during periods of illness
  • before, during and after sport
  • when planning pregnancy, during pregnancy and while breastfeeding (see the NICE guideline on diabetes in pregnancy)
  • if there is a need to know blood glucose levels more than 4 times a day for other reasons (for example, impaired awareness of hypoglycaemia, high-risk activities).
'Proper' testing frequencies of up to 10x a day (and making use of the results) shown to be more effective AND cost-effective. No more shocked looks permitted from non-specialist Drs or nurses suggesting a couple of times a week should be fine.

HbA1c Target
Support adults with type 1 diabetes to aim for a target HbA1c level of 48 mmol/mol (6.5%) or lower, to minimise the risk of long-term vascular complications.

Agree an individualised HbA1c target with each adult with type 1 diabetes, taking into account factors such as the person’s daily activities, aspirations, likelihood of complications, comorbidities, occupation and history of hypoglycaemia.
I've written about this before. Personally, as a patient, I am really pleased with the balance between these recommendations. Don't tell me to be happy with an A1c approaching 8% if there is real evidence that lower is better to guard against long-term complications. Don't tell people who have no problematic hypoglycaemia that their A1c is 'too low' because it's in the 6s (can't get used to the new numbers yet, sorry!). On the flip side, treat me as an individual, don't label me as a failure because you have a magic number in your head that I am working toward, but I'm not there yet.

Not exactly 'CGM for all', but...
Consider real-time continuous glucose monitoring for adults with type 1 diabetes who are willing to commit to using it at least 70% of the time and to calibrate it as needed, and who have any of the following despite optimised use of insulin therapy and conventional blood glucose monitoring:
  • More than 1 episode a year of severe hypoglycaemia with no obviously preventable precipitating cause.
  • Complete loss of awareness of hypoglycaemia.
  • Frequent (more than 2 episodes a week) asymptomatic hypoglycaemia that is causing problems with daily activities.
  • Extreme fear of hypoglycaemia.
  • Hyperglycaemia (HbA1c level of 75 mmol/litre [9%] or higher) that persists despite testing at least 10 times a day (see recommendations 1.6.11 and 1.6.12). Continue real-time continuous glucose monitoring only if HbA1c can be sustained at or below 53 mmol/mol (7%) and/or there has been a fall in HbA1c of 27 mmol/mol (2.5%) or more.
'Consider' is NICEspeak for a much weaker recommendation. It should be on the table, but it's not for everyone. The evidence for effectiveness of CGM was just not compelling enough to do anything else at it's current eye-watering pricetag. To be honest I was shocked at how weak it was, given the experience of people I know who self-fund CGM. Continuous Glucose Monitoring it seems just doesn't do well enough in Randomised Controlled Trials. But at least, here, it *might* be available on the NHS to the people who really need it.

And finally
It was great to see bi-modal (mixed) insulins being given the heave-ho, unless people really wanted to use them. From now on people should be able to start off on a proper flexible MDI regimen from the outset, along with some good education and support.

It was also really heartening to see how NICE reacted to the subject of language. The editors were updating the old recommendations for clarity and new styling (for example 'adult with type 1 diabetes' rather than 'diabetic' or 'patient'). I raised the question of the word control which is a difficult term for some people. Personally I cannot 'control' my diabetes - I do not have the ability to affect all the variables. At best I can limit some, and try to react to, or work around the others. I don't control my diabetes, I manage it. Because of the timing of the discussion, it was not possible given the time-restrictions to change the terminology used in the full guideline (though discussions will be had within NICE for future versions). I was very pleased though that for the 'Information for the Public' version, the phrase 'diabetes control' has been replaced.

What do you think? Will the new NICE guideline make any difference to you? Were you even aware that there was one to cover type 1 diabetes? Let me know in the comments below.

Posted by on Tuesday, 4 August 2015

64 Days with the Medtronic 640G: Ep 5 Changing Infusion Set

I don't know... You wait weeks and there are no turgid video blog posts from me that you need to avoid, and then suddenly two come along within the space of a week.

For this latest episode as part of my 64 days with the MiniMed 640G, I thought I would run through the process of changing infusion set including a walkthrough of the MM640G pump screens. Don't be put off by the hefty 17 minute running time - it's a LOT quicker to do when you aren't waffling on and explaining things as you go.

For what they are worth, I've included some of the little hints and tips I've picked up over the last few years which seem to reduce the number of bubbles I get in the reservior/tubing (everyone's second favourite insulin pump nuisance). This isn't advice you understand, and check with your healthcare providers blah blah blah, but personally I seem to get very few problems with bubbles these days and if any of it gives you some ideas to experiment with for your own set changes then great (but on your own head be it).

The only thing I did not explain very clearly in the video is the importance of using room-temperature insulin. Bizzarely, oxygen is more soluble in colder liquids, so if you fill perfectly and bubble-free with insulin straight from the fridge you can find that you get bubbles emerging from the insulin inside the sealed reservior, after filling, as the insulin warms up. Not helpful.

Anyhow - here it is. Enjoy. And do leave any comments, questions or set-changing tips of your own for me below.

Thanks for watching!


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For an alternative video detailing a set change using Medtronic QuickSets check out this great post by Dave Sowerby.

Posted by on Sunday, 2 August 2015

64 Days with the Medtronic 640G: Ep 4 SmartGuard vs Mountain

We have just returned from a wonderful holiday among the Black Mountains, Brecon Beacons and Cambrian Mountains in the middle of Wales. The weather was as mixed as you might expect, but we did grab the opportunity of one of several gloriously sunny days to walk the popular path up Corn Du and Pen Y Fan which the walking guide proclaims to be 'the highest peaks in southern Britain' (presumably Snowdon counts as ooop North).

It seemed like a reasonable 'test case' for SmartGuard and exercise for me. Things were a little complicated by a fairly active morning with a fairly hefty Temporary Basal Rate which I had slightly overdone so as to be confident to drive, meaning that I approached lunchtime in pretty much double figures (180ish for US readers). Often I would choose to reduce my pre-exercise meal bolus a little, because I tend to get very sensitive to any active insulin once I start moving. I didn't want to do that this time though as I was fairly high to start with and in some dim corner of my mind there is something squirreled away about exercising at high levels being Not The Best Idea.

So there you go... the scene is set, the reality TV style 'manufactured peril' is in place (Solemn face to camera... 'But exercising at those levels, and with all that insulin on board - just what will happen')...

Let the drama unfold.

Oh, and as if that were not enough excitement, you may notice I am sporting an impromptu 'holiday beard' in this video. Feel free to express your opinion, hilarity or horror at this unexpected turn of events by voting #beardyes or #beardno in the comments.

Thanks, as ever, for watching.

Any questions or comments, please leave them below.


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Posted by on Friday, 17 July 2015

64 Days with the Medtronic 640G: Ep 3 What is SmartGuard?

Here's another little update on my time with the Medtronic MiniMed 640G. This time it's a look at what SmartGuard is and how it works. When someone first tried to explain how SmartGuard worked to me I can remember it felt bewilderingly complicated, with all sorts of levels and numbers flying around. Actually once you have got your head around it, I have found it relatively simple - so I'm trying to explain it here with a little animated diagram that tries to work through an example of how and when Smartguard is activated, and what it does.

It should be remembered, of course, that for all it's magic, SmartGuard is not supposed to replace hypo-treatment entirely. Unfortunately for all the over-enthusiastic media hype about the 'Artificial Pancreas' when the MM640G launched, we are nothing like there yet. SmartGuard is a useful step in the right direction, but a full AP it ain't. For starters, there are many situations in which stopping your basal insulin will simply not act quickly enough, or have enough impact, to head off an impending low. And there are other situations where SmartGuard might be triggered for all the right reasons, but not actually have been needed and you end up higher than you'd like because of it.

I'll cover some of those situations in more detail in another blog - but for now, let's focus on those gentle (or not so gentle) drifts below 4.0 which SmartGuard effortlessly squashes without bothering you with any irritating alarms.

When it works well, it genuinely feels like you have a little 'diabetes helper' by your side, actively looking out for you. Not something I have ever felt about any other piece of diabetes technology.

If you have any questions or comments, please do leave them below. I'd love to hear what you think.


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