Control IQ with Tandem Diabetes

FULL REVIEW: Control IQ with Tandem Diabetes

Omgosh!! It’s really is almost here (always with the almost), but Control IQ should be out to the public by late January 2020.

How Control-IQ Technology Works on the t:slim X2 Insulin Pump - YouTube

As a Registered Dietitian Nutritionist and a Certified Diabetes Specialist and healthcare provider and a pump trainer, I was given early access, so I’m here to give you my review of Control IQ.

So how does this update work?

In this review, I will state the Control IQ features, then I will break down the real-world application of what each feature means and how it will affect your diabetes management. Lastly, I will close with the outcomes from the 6 month Landmark Study used by the New England Journal of Medicine. As a side note, I am not yet on Control IQ, I wanted to give this review first. I will be on it in the near future, and I will post my review on this blog and on my YouTube Channel.

Benefits of Control-IQ Advanced Hybrid Closed-Loop Technology:

#1 Predicts and helps prevent lows and highs – Control-IQ technology uses CGM (Dexcom G6) readings to predict glucose values 30 minutes ahead and can increase, decrease or stop basal insulin delivery to help keep your blood sugar in range (70-180 mg/dL).

#2 Automatic Correction Boluses – If blood sugar is predicted to be above 180 mg/dL, Control-IQ technology calculates a correction bolus with a target of 110 mg/dL and delivers 60 percent of that value. During it’s normal settings (AKA not exercise of sleep settings) it will do this up to once every hour.

#3 Accommodates for sleep and exercise – Control-IQ technology offers optional settings for sleep and exercise that change the treatment values to better match the different physiologic needs during these activities.

#4 No fingersticks – With Dexcom G6 CGM integration, the Control-IQ feature works with no fingersticks required for mealtime dosing or calibration.2 Other benefits of the Dexcom G6 CGM include an extended 10-day wear, acetaminophen blocking, and the ability to share real-time CGM data with up to 10 followers.

#5 Easy to use – The system has no complicated criteria to keep Control-IQ technology on. If the CGM signal is temporarily lost, the Control-IQ feature will resume automatically when the CGM is back in range. In the pivotal study, participants gave Control-IQ technology a 4.7 out of 5.0 for ease of use, and a 4.8 out of 5.0 for desire to continue use of the system.

And now for MY breakdown of each feature:

#1 Predicts and helps prevent lows and highs (70-180mg/dL). Most people with diabetes care to have more time in range and especially when it doesn’t require any additional work from him/her. My issue is the parameters. For those who love tight time in range and A1c in the low 6s and 5s, to be blunt, Control IQ will likely not be your fix-all.

The happy place for Control IQ is between 112.5 mg/d – 160 mg/dL. And this set boundary is non-negotiable, meaning you can not change this range. This also means that only if your blood sugar is predicted to hit about 160 mg/dL within 30 min, will your pump increase your basal, and if your blood sugar is predicted to fall below 112.5 mg/dL (which seems to be a very random number, I know) within 30 minutes, your pump will be adjusted to give you less of your basal.

As a side note, Tandem uses your programmed basal at it’s launching pad, then adjust your programmed basal as your blood sugar goes up and down past the set parameters. If you use different profiles, you are encouraged to continue to do so, and Control IQ will work with whichever personal profile you are actively using.

About the 112.5 – 160 mg/dL parameter. To me, to be 100% frank, I’m a bit dissapointed about this. I like my blood sugars to stick between about 80-120 mg/dL.

Yes of course it goes above (and below) that range, I love popcorn and likely too much fruit. However, this is my personal happy place. With the algorithm used to Control IQ, you could technically sit as high as 159 mg/dL all day, and your pump would not be prompted to give you any extra basal. Which wouldn’t happen, but it’s good to think about. However, with that logic, your blood sugar could also be set at 113 (sorry, I meant 112.5 mg/dL), which is a happy place to be, for me at least. Looking at this range, best and work case scenario, if your blood sugar were to sit at either spectrum of the range all day, would be the following. 159 mg/dL = 7.2% 113 mg/dL = 5.6%

Again, your blood sugar is NOT going at one number all day, but knowing when the pump will be triggered to either increase or decrease the basal is important when considering if Control IQ is a good fit for your diabetes management goals. Below is a picture of the 5 tier algorithm basal delivery system used for the Control IQ.

Control-IQ hybrid closed-loop system | for healthcare providers

Below is more in-depth of each of the following tiers.

1. Delivers [above 180 mg/dL] An automatic correction bolus occurs if the sensor glucose is predicted to be above 180 mg/dL. The amount given is 60% of your usual correction dose, and the target blood sugar is set for 110 mg/dL. This can occur as often as every 60 min (this feature does not work during the sleep or exercise setting).

2. Increases [Between 160-180 mg/dL] If your blood sugar is predicted to go above 160 mg/dL within 30 minutes, you will receive an increase in basal (but not automated bolus).

3. Maintains [Between 112.5-160 mg/dL] This is the happy place according to your Tandem pump. Your pump will give you your usual set basal if your blood sugar is predicted to stay within this range.

4. Decreases [Between 112.5-70 mg/dL] If your blood sugar is predicted to go between 112.5 and 70 mg/dL, then your basal will be decreased, but NOT stopped.

5. Stops [below 70 mg/dL] When your blood sugar is predicted to go below 70 mg/dL within 30 minutes, your basal will be suspended. Now for the next feature…

#2 Automatic Correction Boluses This is the only hybrid closed-loop system that has automated correction boluses, so this feature is awesome. Currently, Medtronic (the 670G) and DIY looping do not have automated correction boluses, but in order for this correction bolus to happen, your blood sugar has to be predicted to go above 180 mg/dL within the next 30 minutes.

Note that this in reference to the correction, NOT mealtime bolus relating to food. But we are getting closing to full automated bolusing with correction AND mealtimes.

With the Control IQ correction bolus, the IOB is on board is taken into account, and delivers 60% of your set correction bolus with 110 mg/dL as the set target blood glucose in order to avoid risks of hypoglycemia. This correction bolus happens every 60 minutes. This feature does NOT work during sleep, but sleep activity is a tighter range. Again, I wish that this could be set for a lower parameter, but Control IQ is to help the masses to have more time and range and less swings (and to do this safely).

Next feature…

#3 Accommodates for sleep and exercise Control IQ allows you to have too optional settings for sleep and for exercise. During these modes the algorithm targets changes to help you lessen lows and to increases time in range with less swings. Below are the parameters for the exercise basal algorithm.

  • Automatic Correction Bolus: Above 180 mg/dL
  • Increase Basal when above 160 mg/dL
  • Decrease Basal when below 140 mg/dL
  • Stop Basal when below 80 mg/dL

So the difference with exercise mode is that insulin is decreased when your CGM reading is below 140 mg/dL (compared to 112.5 mg/dL), and stopped when below 80 mg/dL (compared to 70 mg/dL).

As for sleeping, automated correction boluses are disabled, however, during sleep, it will gradually intensify control overnight by tightening the treatment range to 112.5-120 mg/dL To access the exercise mode, toggle it on your pump. Why can’t it be the parameters for 112.5 – 120mg/dL be set for all day?!? But part of the reason this tightened spectrum can be achieved during sleep mode is that you don’t have food bolus and spontaneous activity involved.

To access the sleep mode, you can toggle it on as long as you are about to sleep for 5+ hours. You can also create a sleep schedule of your usual sleep patterns to make this function run more smoothly. Below is a picture to show you how to create a sleep schedule (you can create more than one: for example, work week vs weekend). However, you will learn more about this during the online training or during a pump trainer with your Tandem pump trainer.

The next feature…

#4 No fingersticks – Hello!! Yes. This is great, but this isn’t new news for people on dexcom G6, but Control IQ only works with Dexcom G6. Tandem is investigating ways to be more open-source to allow you to chose your CGM and pair with Tandem, but for now, Dexcom G6 is the must CGM for Tandem software. What I want to make a special note is that you do NOT have to enter your BG sensor reading when you are bolusing when Control IQ is on. So when you go to your bolus screen, your blood sugar should automatically be populated if you are currently getting CGM readings. Which is NICE!

The no fingerstick feature is important because the other FDA-approved hybrid closed-loop system is the Medtronic 670G which currently requires 3-4 calibrations AND recommended blood sugar test for meal or correction dosing. Medtronic is actively working on non-adjunctive labeling which reduces total blood sugar pokes, but it will likely not be 0 pokes like Dexcom anytime soon. With Dexcom, it is technically 0 pokes. Which I love, but that doesn’t mean you should be checking when you feel the CGM reading is off.

Unfortunately, these sensors can be grossly off at times, so if you are about to give a big correction for a high or eat your weigh-in smarties candy for an urgent low, check your blood sugar FIRST. There is nothing more annoying, then to give a big correction based on your CGM reading, then find that your CGM was actually fine, so now you are frantically shoveling in stale Halloween candy to avoid a scary low.

But yes, the no fingerstick feature is nice. Dexcom G6 is commonly used with the DIY (off-label use) closed-loop system with Omnipod, so that isn’t new there, but it is new compared to Medtronic 670G. The last feature… #5 Easy to use – I have extensive training and experience with each pump (FDA-approved and not) and based on the training, I believe (since I do not have it on yet) Tandem Control IQ is the easiest to use thus far.

Currently, I do use an Omnipod for off-label use to loop, but this system has bugs…constantly. I enjoy it because it allows me to set my target blood sugar ranges, improves my sleep, allows me to bolus from my iPhone and iwatch (which I love), and many other benefits (I’ll get into in another post), and I LOVE being tubeless.

But, I feel there is usually some sort of little bug going on that I’m having to figure out. Not to mention, you need access to expensive tech and you have to build the app, although there are wonderful resources to get you start. HERE for more information on looping.

So yes, Tandem is easy to use compared to the other HCL available. It’s simply a toggle. I would say that it’s easier than Medtronic 670G although the process of turning on is the same, the amount of work to stay in automode for Medtronic is much more labor intensive and can greatly decrease your sleep quality with blaring calibration or BG (blood glucose) test alarms. Lastly, let’s look at the study that shows the outcomes of the Control IQ software.

The NEJM Publication of Landmark Study NEJM (New England Journal of Medicine) This is full 6-month landmark study used to see the outcomes of the Control IQ. We won’t go into full detail about that trial, but you can access the full trial here. To look at the outcomes, I put this graph together to compare the baseline vs Control IQ.

* This means that that there was 2.6 hours more in Time in Range per days. ** And without hypoglycemia (actually a reduction in lows)

Final Notes on Control IQ: If you don’t have a Tandem, but are curious to try it, you can access the free demo app with their t:simulator App. This app is free and it allows you to experience the touchscreen and interface of the t:slim X2 pump with the Control-IQ technology on your smart phone. Also, make sure to talk to your provider and your insurance to investigate what is covered and what are your options.

Again Control IQ is totally free of charge for all in-warranty t:slim X2 pump users in the United States. All you need is to registered your current t:slim X2 pump on the Tandem website, wait for the Basal IQ email, download the desktop app, then connect your pump to your computer with a micro USB cable to download the Control IQ software update.

As a side note, the Control-IQ feature will require you to secure a new prescription from your provider, but your provider should have received a rx form to send to Tandem to accept all of their patients long before you were able to update your pump (AKA you shouldn’t need to contact your provider). However, as always, in no way do you have to update, it is YOUR personal decision on if and when to do this update. In my next post, I will give you my Hands-On Experience! In my hands-on review, I will let you know how it goes actually using the device. All of this material provided is through my training, but I will be on Control IQ and will let you know what I think. Expect this in 1-2 weeks. I will be posting my review on Youtube Channel and on this blog.

As always, if you need help with your diabetes management, or you feel it would just be nice to have someone who understands diabetes to cheer you on and tell you how amazing you are? Send me a message or schedule with me on my blog so we can work together. I understand I am an odd duck who apparently can’t get enough of diabetes, but I absolutely love working with people just like you. A little about me: I work as a Registered Dietitian Nutritionist, a Certified Diabetes Educator, a Certified Pump Trainer, and a T1D (for street cred), I have the credentials, schooling, education, and experience to help you get your life back. If you need help with your diabetes, write me a message so we can work together. I work with people with T1D through online video calls all across the United States through my online telehealth private practice. Working with people to reach their diabetes, weight, and fitness goals is what I love to do. I also work as a CDE and an RD at an Endo clinic where I get to work with people with diabetes in-person. If you are burned out, or just plain sick of diabetes, send me an email. Tell me what’s going on and ask me any diabetes-related questions. I am on your side and I want to help you.


Ariel Warren, RDN, CD, CDCES

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