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ALICIA-unleashedAlicia: UnLeashed!

My Personal Review of Tandem Diabetes’ Control IQ (CIQ) hybrid closed loop system

tandem Diabetes control IQ closed loop system

2 weeks on Control IQ – too soon to call? Our newest Hybrid Closed Loop showing a lot of promise… if you know how to work it.

About 3 weeks ago we got news of the FDA approval of Tandem Diabetes’ Control IQ (CIQ) hybrid closed loop system. As the practice’s resident X2 pump user I was more than happy to take a break from looping to give the system a try. It’s been about two weeks and I’ve learned a lot and can honestly say I really like this system. I wanted to share my findings thus far.

This is my personal review, other members of our team will give it a trial and we will compare notes and experiences and come out with more “official” reviews and recommendations.  However, with so many people so eagerly awaiting this system, I thought I’d share what I can now.

I will start by saying don’t buy ALL the hype!

Every time we get a new system we are always told that: it is going to make things better, you won’t have to think about your diabetes anymore, the system does all the work of adjusting insulin!

I can tell you right now this system is not an artificial pancreas  (which Tandem never claimed it to be) and it is not a simple fix for all diabetes management problems. In fact, my first few days on Control IQ were a complete nightmare! (I didn’t end up in the hospital , but I had a multi -day headache from sustained high blood sugars that I couldn’t beat down using the system) This is a CHANGE in how we manage our diabetes, so it is to be expected that just tapping the system on and trying to manage your diabetes as usual is not going to work.

Automated insulin delivery is often sold as if we are going from driving a stick and grinding gears, to driving an automatic with heated seats and extra cup holders. In fact, it’s like going form driving a horse and buggy, to driving a stick. It is a lot less work, but the work is definitely still there, Once you get good at it, stop stalling and grinding gears ,you can get where you want to be with a lot less… cleanup.

How does this Hybrid Closed Loop system work anyway?

In the simplest terms, Control IQ works by targeting a blood sugar of 110, when predicted (30 minute prediction based on previous 20 minutes of movement) blood sugar is above 160 basal is increased, when predicted BG is above 180 it auto-boluses . When predicted BG is below 112.5 CIQ reduces basal delivery, when predicted BG is below 70 it stops basal.

Here is a link to Tandem’s information on the system. Tandem has webinars rolling out to educate on the system ahead of its general release later this month.


My personal experience with Control IQ and the biggest differences I’ve experienced.

  • No more stopped extended bolusing

Since CIQ is easing back on basal as blood sugars drop and is much more conservative about stopping delivery entirely, we no longer get the headache of setting an extended bolus for dinner and going to bed at 110 only to wake up three hours later at 240 because the system stopped the last third of our bolus!

We can extend bolus with CIQ (Something the Medtronic 670G can not do) and as blood sugars come down basal is reduced rather than the bolus cutting off. I have seen blood sugars come down to 95 and park there for the night!

  • Really effective handling of mild metabolic changes

CIQ is quite good at dealing with hectic changes in activity level and metabolics as long as they are not too big. I am a mom of a toddler, so jumping up and running around for 40 minutes, or sitting bogged down in paperwork for hours, are all a part of a single afternoon in my life! From what I’ve experienced CIQ handles these quite well, with small ripples in blood sugar movement.

I typically run a temp basal or two every day for these kinds of changes in my activity, health, stress etc. But, I have not run a  single temp basal for the last 6 days! In fact, there were probably some times I would have missed that CIQ caught and made much easier.

  • Big metabolic changes are too big for CIQ, but there are workarounds

My first 5 days on CIQ were ROUGH!! I had some hormone swings and a sinus infection that really beat up my blood sugars. Even after I got the system’s other setting needs dialed in, CIQ alone was not enough to keep my blood sugars from jumping up , particularly after high fat meals which would require an additional basal increase beyond illness. At first I turned off control IQ and handled it manually like I usually would, but then I started experimenting. I found that building a second profile with my basals set higher allowed CIQ to then increase delivery from that starting point and handle sick days really effectively. Better yet, when I started feeling a bit better and BGs came down, I did not slam low like a yard dart! CIQ eased back on basal deliver enough to let me sit nicely and safely for hours (Even on a night that got busy with patient needs and I skipped dinner) This would not have been the case if I were just running my own sick day temp basal increases!

I have not had much change in my exercise management. The exercise targets in CIQ still need to be set an hour or two in advance of exercise and have only been enough of a reduction in insulin to get me through low to moderate activity which is no different form running a temp basal for the same situations. I still have to adjust my bolus in advance of moderate or higher physical activity to avoid a drop. I can see this being helpful to reduce lows during unanticipated play time for kids when pediatric approval comes through. The reality of aerobic exercise is that we have to reduce the insulin we have active in our bodies, and those decisions have to be made hours in advance, or be considerable in size.  No  HCL on the market can do that on its own, since our insulin lasts for hours in our bodies.

  • Longer DIA & more IOB = big changes in bolus effect

The biggest hurdle I met with CIQ was the difference in Duration of Insulin action(DIA). This is one of the few hard wired settings in CIQ. It uses a DIA of 5 hours. (We could debate the validity of this for longer than the DIA of Tresiba so we’ll skip that) My typical DIA is set for 3 hours 15 minutes. This means that a correction bolus 3.5 hours after a meal would be HUGELY reduced! This was very problematic and compounded by being sick! I was actually wondering if my insulin had somehow denatured!

This was then also compounded by the fact that CIQ  counts my manual bolus, and its autobolusing  toward IOB calculations. And if the math of these IOB calculations predicts that blood sugar will return to target it will not increase basal. So here I was with a blood sugar of 240, a pump telling me that due to IOB I would go low, and no basal increase, FOR HOURS! I also found that over night when I should have zero IOB control IQ just was not ramping up basal enough to get my blood sugars below about a 140. This is not damaging, but I’ used to waking up at 100, so it was disappointing. That’s when I realized that in order for Control IQ to appropriately treat my elevated blood sugar I was going to have to reduce my correction factors.  I ended up having to decrease those factors pretty significantly during the daytime and evening hours, and a bit less aggressively over night. After that things dialed in very nicely. The added insulin from the changed ratio was able to balance out the decreased insulin from the longer DIA and inflated IOB calculations. **HOWEVER** I still kept a profile with manual settings so that if I am running for any extended period in manual mode and basing my corrections off my shorter DIA, I wont send myself plummeting.** For anyone counting that means that I am using 3 profiles to operate CIQ effectively: my manual settings tested and proven(Alicia) , my CIQ settings with more aggressive correction ratios (Alicia IQ) and a set with control IQ correction factors but higher basal settings for sick days, hormone shifts etc (Alicia HIGH IQ… No pun intended, and actually, probably not accurate anyway)

  • Sleep schedule can get in the way, time it well

Another great feature is the sleep schedule. While we are sleeping targets tighten in and drop to buy us some valuable A1C lowering time over night. But the down side is that it stops auto-bolusing .  Blood sugars will come down over the entire night. But a high BG would not get the “hammer” of a bolus applied. The “Sleep” feature can be turned on /off, or scheduled. The first few nights I set the time to start when my head hit the pillow .(Again, I’m a toddler mom so this is usually as early as possible!) What I found was that there was not quite enough time for CIQ to “Fix” my blood sugar before I went to bed. If I ate dinner at 7 and went to bed at 930 and was riding a little high the system struggled increasing basal all night only to get my to a 130 in 8 hours. Again adjusting correction ratios helped some. But, I found that making sure to schedule my sleep time to not start until dinner had plenty of time to get back down to target was more effective. I pushed my sleep program start time back a couple of hours and voila! I was back to target in a few hours and then watched blood sugars snuggle in nice and low for the rest of the night.

  • Extended bolusing past 3 hours is my biggest challenge

We are able to extend boluses in Control IQ  which is a huge step up from Medtronic’s 670G HCL, but extensions are limited to a 2 hour duration. This was my biggest hurdle and I am still working on this piece. Anyone who uses a bolus extension beyond 2 hours in length (particularly those who have gastroparesis, night time digestive slowing, chronic constipation, eat a low glycemic index diet , eat large meals etc) is going to have to “relearn” how to handle these boluses. I have found that manually splitting my bolus to take about 70% of my bolus ahead of the meal, increasing the front end of the extended bolus and only extending for 1 hour, then manually bolsuing the remainder of the carbs over a 2 hour period has worked in place of my previous 50/50 over 3 hours bolus. But I am having to do a bit of work on analysis of my foods and retool my approach. This is a small step back since I’ve had years of knowing my “Go to” bolus splits and timing for lots of foods. But, the reality is that every single HCL available (including Loop) has required me to adjust my thinking and approach to how I bolus. This is a change in thinking that is going to be necessary with any of these systems and likely in how diabetes will be managed in the future, so may as well reconcile myself to that now and grow rather than get rigid and break later.

  • Only one new alert!

CIQ alerts if an autobolus has been administered and BG remains above 200. This is the only alert I’ve gotten from the system (I’ve not been “kicked out” or demanded of in any way!) And since I get a dexcom alert for highs over 200 it was no added burden.

  • Disconnecting

Tandem users often just disconnect without stopping insulin delivery since the X2 has a loud alert after 20 minutes that could scare the wits out of the entire swim team! However, on Control IQ this would really mess up IOB. If  disconnecting for 20 minutes or less just stop insulin. If you are disconnecting for more than 20 minutes you’ll want to turn off Control IQ and disconnect as usual to prevent messing up your IOB. (remember if you’re disconnecting for an extended period you’ll want to reconnect hourly to replace basal)

  • Tight control is possible

To see what the system would do I got my blood sugar to 80 and carried about my day. Control IQ not only let me get my blood sugar to 80, it allowed me to ride between 80-95 all day! This is the first FDA approved HCL that is even capable of an A1C of a 6! That was exciting!

With these adjustments, I’m now sitting on day 5 without a single high or low alert. I’ve worked out, I’ve eaten big meals, I’ve skipped meals and I’ve dealt with some wildcards life threw my way. I have not run a single temp basal, stuck my finger, or had sleep disturbed by diabetes. This is not the simple diabetes “fix” some would make it out to be, but it is miles ahead of the past and with the right education and support can really be amazing. However, with settings that are not dialed in, unknowing providers and incomplete support users will likely be in for a bumpy ride if not a disappointing mess.

  • Random perks

  1. Bluetooth connectivity- We now the option to pair my pump to a mobile device via bluetooth to transmit data to the T-connect app, but since that app has not released yet we don’t know what it will actually do or whether we will be able to sync this data to other sites.
  2. One less beep- We now have the option to turn off that dreaded tube fill beep that is loud enough to wake the neighbors! However, the charge beep remains (Come on Tandem at least let us set it to vibrate!!)
  • The real question comes down to

“OK Alicia which is better? Loop or Control IQ?”

Honestly, that is going to depend entirely on the individual.

Looping allows for more individualized control and more aggressive targets; no tubing with omnipod Loop and more sophisticated handling of bolusing and metabolic changes.

Tandem X2 with Control IQ allows for good control with all the support of an FDA approved device; with nothing extra to carry and there is less troubleshooting when something goes wrong.

For me the question is now “Which is better?” but “Do we have a viable alternative in Hybrid Closed Loop therapy?” From what I’ve seen, my answer would be yes. I don’t want one company to win over another, I want us to have more options to meet our differing lifestyle and management needs. I am thrilled to report that it looks like we finally have another new option.

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