#tandemsummmit2020 was everything I’d been hoping for! I wanted to first and foremost thank all of YOU for getting me here. Thanks to your support, and your voting, I won the Diabetes Blog of the Year award at the #myabeticdiabetesawards and with this award, came a scholarship to attend the Advanced Technologies and Treatments for Diabetes and a Tandem community relations summit in Madrid, Spain! At the summit we learned all about Tandem’s new Control IQ, Though many of you are now on, or awaiting upgrade to this system, I thought it would be helpful to review some of the algorithm details here. So here’s the coolest part...we now we have two “hybrid closed loop systems” to choose from- control IQ and 670G. Choice is EVERYTHING! It’s difficult to compare the two systems. They are both so different! I’ve done many posts highlighting the Minimed 670G already so I’ll give a quick review and then dive into Tandem. Minimed 670G system auto adjusts insulin every 5 minutes based on the algorithm which adjusts based on TDD, sensor rate of change, time away from target, and insulin on board. While in auto mode, manual basal settings are NOT used. Neither are correction factors or BG targets. When using Control IQ, SETTINGS MATTER! All manual settings are used except target and duration of insulin action, which is set at 5 hrs. There are three activity settings in this new algorithm; Control IQ, exercise activity, and sleep activity. In normal Control iQ, programmed settings are used when the person’s CGM readings are trending between 112.5-160mg/dL, Basal will increase if the glucose is predicted to be above 160mg\dl within 30 minutes and a correction bolus will be given if the glucose is predicted to be >180mg/dL within 30 minutes. Correction boluses can be give 1x/hr and are 60% of the programmed recommended correction. Basal will decease if the sensor glucose is predicted to be <112.5mg\dl and will stop if predicted to be <70mg\dl in the next 30 minutes.
In exercise activity (manually turned on my the user), basal rate remains as programmed if the CGM readings are between 140-160mg/dl. Just like in the Control IQ setting, an increase in basal will occur if sensor glucose is predicted to be above 160 mg/dl and a correction will be given if predicted to be >180mg/dL within 30 minutes. Basal insulin will decrease if SG values are predicted to be below 140mg/dL and basal delivery will stop if predicted to be below 80mg/dL within 30 minutes. In my experience, turning on exercise mode 1-hr before exercise (like I normally do) was not enough to prevent lows during my workout. On the tandem pump, you can create up to 6 profiles and I therefore created a profile that was 50% of my usual basal and began setting that profile 1-hr before exercise in addition to turning on my activity mode. I was then going into exercise with more reasonable with more elevated BGs which in turn caused Control IQ to give me a correction. Because the correction given in activity mode is 60% of the recommended correction bolus, I weakened my correction factor on my new activity profile. That seemed to work much better. Does any one else have a suggestion for dealing with high intensity exercise on this system?
Lastly, let’s discuss sleep activity (present by the user and turns on automatically). Programmed basal rates are used when the patient is trending between 112.5 and 120mg/dl. Basal will be increased if the sensor glucose is predicted to be >120mg/dL within 30 min. Corrections are NOT given in this mode-so all of you who are running sleep mode all the time (yes I’m talking to you)-realize that you are not getting the benefit of auto corrections for high BGs. Basal is decreased when the sensor glucose is predicted to be below 112.5mg/dL and will stop if sensor glucose is predicted to be <70mg/dL within 30 minutes.
Also of note, extended bolus can still be used in control IQ (great for high fat meals or people with gastroparesis).
I really enjoyed my experience on this therapy. I spent 100% time in range for 3 days straight! My only issue was with my exercise...no I did not exercise on those perfect TIR days. I was only able to do a 10 day trial, but I look forward to trying it again to see if I can get that exercise figured out.
Anyone else have good experiences with control IQ?
