by Steve “TIR” Edelman
Time in Range (TIR) Is the Hot New CGM Metric.
Improving your time in range (the percent of time you are between 70 and 180mg/dl) is extremely important, and truly represents how your control is on a day-to-day basis. This range of 70 to 180mg/dl represents where your glucose values should ideally be before and after meals. The goal TIR for most people with diabetes is 70% or higher.
How Can You Improve Your Time in Range Solely by Adjusting Your Alerts and Alarms on Your CGM?
I will tell you what I have learned from my patients using CGM devices, and from my own experience. Most diabetes professionals will tell their patients to set their upper alert at 180 to 200 mg/dl and their lower alert at 70 to 80 mg/dl. The problem with these settings is that once you hit the upper limit of 180mg/dl, or the lower limit of 70mg/dl, you are already out of range, and your TIR percentage will drop (not to mention the annoying high and low glucose values).
Why Not Lower Your High Alert and Raise Your Low Alert So You Can Act Well Before You Hit the “Out of Range” Values?
I lowered my upper alert from 180 down to 150mg/dl, and that has made a huge difference in raising my TIR from the low to mid-70s to ~ 85 to 90%…seriously! When my CGM alerts me at 150, I look at the trend arrow and then decide to either give a correction bolus (if the trend arrow is diagonal up or straight up) or do nothing and observe over time if the trend arrow is horizontal. This way I can avoid hitting 180 and improve my TIR. Even if I do cross that 180 upper limit, the time to return below 180 is shorter.
One Very Important Suggestion I Have Is to Change the Way You Think about the High Alarm.
I used to hate that obnoxious two beeps when I hit 180, and I typically would say “son of a bitch” or “damn” to myself…or to anyone who would listen! Now I say “awesome” because I can do something proactively to keep me in the range! The other thing I did was to change the alert sound. The Dexcom CGM has many different sounds to choose from, and I picked the one called nerd alert because it is subtle and not annoying to me. I actually love that sound now!
On the low end, I changed my low alarm from 70 to 80mg/dl for the same reason – to be notified before I hit the lower TIR limit of 70 mg/dl. The alarm sound I picked was crying baby as it typically makes me laugh and gets all kinds of comments from people around me. It also reminds me of Jeremy when I beat him week after week in our TIR contest.
There You Have It, Folks!
You can for sure improve your TIR solely by adjusting your alerts and alarms, and by changing your attitude about the concept of “alarm fatigue”. Remember…your alerts are your friends. Learn to love and embrace them!