The CGM Blog

Breaking Down Time in Range: A New Way to Think About Glucose

People who live with diabetes spend a good part of each day trying to make sure their glucose levels stay where they are not too high and not too low. You might call it your target glucose range or sweet spot.

Ideally, you want to spend a greater portion of your day somewhere in the middle. The percentage of time you spend in that range that’s both not too high and not too low is known as your Time in Range (TIR). For someone living with diabetes, knowing TIR can help give you a more complete picture of your glucose and how to manage diabetes today, and in the future.

What is Time in Range?

Time in Range in diabetes is the percentage of time spent with glucose levels in a target range. You should work with your healthcare provider to determine your personal high and low levels for your target range and what your percentage goal should be. Think of TIR as the number of hours in a day you spend in your sweet spot. For example, if your TIR percentage is 50%, that would mean that you are within your glucose target range for half the day or 12 hours.

TIR is a fairly new measurement, best measured by continuous glucose monitoring (CGM) systems. Today, TIR is an effective metric for healthcare professionals and people living with Type 1 and Type 2 diabetes to evaluate if glucose goals are being met.

The goal for someone living with diabetes is to keep glucose in range for as much of the day as possible, but how do you keep track of your TIR? A fingerstick and glucose meter result is like taking a single snapshot of your glucose, it only tells you where your glucose is in that moment. A continuous glucose monitor, like the Dexcom G6 CGM System, can give you your glucose reading in real-time, continuously and with no routine fingersticks* or scanning needed. Readings are sent to the Dexcom G6 app on your compatible smart device up to every 5 minutes.^† With just a glance, you can see your glucose number and a directional arrow to quickly see where your glucose is trending and how fast.

For a daily, weekly, or monthly view, Dexcom G6 users can access their past glucose data in the Dexcom CLARITY app which can show you your TIR and other important metrics.

Why is Time in Range Important?

The more people living with diabetes spend in their target range, the better and healthier they report feeling.¹ A higher TIR percentage is correlated with a lower A1C.² A recent study showed that a 10% increase in TIR is like a 0.8% reduction in A1C.2 For example, say you increased your TIR from 50% to 60%, you might also see a reduction in A1C from about 8.3% to about 7.5%.

Keeping a close eye on your time in range can help you set goals for your diabetes management, which can be especially useful in between clinic appointments. That’s where Dexcom CLARITY comes in. The Dexcom CLARITY app can help you pinpoint which times of day you might be trending high or low. You can also opt in for weekly notifications from the Dexcom CLARITY app that tell you if your weekly TIR has gone up or down. Glucose data can also be shared automatically and securely with your health care team. All of this makes Dexcom CLARITY a powerful tool to help make clinic visits even more efficient.

What Should My Time in Range Target Be?

Everyone’s target glucose range is unique and should be discussed with a physician. Generally, most people start at a range of 3.9 to 10 mmol/L. These targets have been broken down into daily goals and according to the International Consensus on Time in Range, people living with diabetes should aim to spend:³

Suggested Target³	Approximate time in hours
At least 70% of the day between 3.9 to 10 mmol/L	About 17 hours per day
Less than 4% of the day below 3.9 mmol/L	Less than 1 hour per day
Less than 25% of the day spent over 10 mmol/L	Less than 6 hours per day
Less than 5% of the day above 13.9 mmol/L	Less than 1 hour per day

Don’t worry if you are not meeting these goals, though. Aim for small improvements because every 5% increase in TIR matters.³ Simply put, reducing time below 3.9 mmol/L and above 13.9 mmol/L can lead to a higher TIR. But be sure to discuss your goals with your healthcare professional!

How can Dexcom CGM help?

Dexcom CGM use has been clinically proven to improve time in range and A1C.^4,5 With no need for painful routine fingersticks* or manual sensor scans, Dexcom G6 can help alleviate some of the burden of diabetes management so you can focus more on doing the things you love. It puts the power of real-time glucose data and insights into your hands so you can make better decisions in the moment.

Learn more about the Dexcom G6 CGM System here. Need help with insurance coverage? Speak to our team of Account Specialists to take the next step towards improving your Time In Range.

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*If your glucose alerts and readings from the Dexcom G6 do not match symptoms or expectations, use a blood glucose meter to make diabetes treatment decisions.
† For a list of compatible smart devices, please visit dexcom.com/compatibility.
1 Dexcom, U.S. data on file, November 2020
2 Vigersky RA, et al. The Relationship of Hemoglobin A1C to Time-in-Range in Patients with Diabetes. Diabetes Technology & Therapeutics. Feb 2019.81-85.
3 Battelino T, et al. Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range. Diabetes Care 2019 Aug; 42(8): 1593-1603.
4 Beck RW, Riddlesworth T, Ruedy K, et al. Effect of continuous glucose monitoring on glycemic control in adults with type 1 diabetes using insulin injections: The DIAMOND randomized clinical trial. JAMA. 2017;317(4):371-378.
5 Welsh JB, Gao P, Derdzinski M, et al. Accuracy, Utilization, and Effectiveness Comparisons of Different Continuous Glucose Monitoring Systems. Diabetes Technol Ther. 2019;21(3):128-132.