What is it?
Time in range (TIR) is the percent of time a person’s blood sugar is in the targeted blood sugar range. General guidelines recommend a target range of 70-180, and aiming to stay in that range at least 70% of the time. This means the blood sugar is in range (between 70-180) about 17 out of 24 hours during the day and would be equal to an A1C of 7%.
Continuous Glucose Monitor (CGM)
With a continuous glucose monitor (CGM), users are able to do just as the name says, see what their blood sugar is doing at any point during the day. A CGM not only gives users information about how much time they spend in, above, or below, the ideal target blood sugar range, but it can also help users see other things. For example, a person would be able to see blood sugar trends, how their blood sugar changes throughout the day, and see how other factors can affect their blood sugar like caffeine, stress, exercise, etc. By looking at these things, an individual can learn how and when to make changes to help improve their blood sugar and TIR.
Why Does it Matter?
Keeping blood sugar within range, or even improving the TIR, can improve quality of life in several ways. Mood, energy, hunger, and sleep will all feel quite different when in range vs above or below range. Additionally, keeping the blood sugar within range more often can help reduce the risk of complications.
TIR with a Blood Glucose Meter
If you don’t have a CGM, you can use a blood glucose monitor (BGM) to estimate your TIR. The more finger sticks you do during the day, the better idea you will have of your TIR. It is best to get readings for two weeks and at various times during the day and night. Several apps, websites and blood glucose monitors have TIR calculators you can use, but if you do not have access to any of those you can use this equation:
The number of blood sugar readings in range (between 70-180), divided by the total number of blood sugar readings, multiplied by 100.