In 2021, Diabetes Canada released updated Clinical Guidelines on Blood Glucose Monitoring. These guidelines include new CGM terminology, as well as clinical guidance for CGM in Canada, including TIR.2
International Consensus Report on Time in Range
The International Consensus Report on Time in Range (TIR) recommends that most people with diabetes spend at least 70% of the day (around 17 hours) in the target glycemic range of 3.9 to 10 mmol/L, which corresponds to the recommended A1C target of approximately 7% (53 mmol/mol).1
Dr. Alice Cheng, University of Toronto, explains how the targets from the International Consensus Report may be applied in clinical practice.
The report was endorsed by eight international professional associations* in 2019 following the Advanced Technologies & Treatments for Diabetes (ATTD) Congress.1 It presents guidance to support healthcare professionals and people with diabetes in using continuous glucose monitoring (CGM) data to identify metrics of glucose control, including TIR.1 Specific targets for people who are older, high-risk, or pregnant women with type 1 diabetes have also been recommended.1†
CGM-based targets for different diabetes populations according to the International Consensus Report.1
A deeper dive into the International Consensus Report and guidance recommendations
Following the publication of the International Consensus Report, Diabetes Canada published their 2021 Clinical Practice Guidelines on Blood Glucose Monitoring. These guidelines included TIR as an important metric for people to assess glucose levels using CGM.2
TIR is having an increasing impact in the world of diabetes research. While A1C is an important metric, there is now a growing body of evidence supporting TIR as a valuable endpoint in clinical trials.2-5 Clinical research suggests that the more time a person with diabetes spends in range, the greater their chance of reducing their risk of long-term diabetes-related outcomes.6-10 The following is an overview of the current guidance related to TIR:1
- The recommended glycemic range for most people with diabetes is 3.9 to 10 mmol/L. This corresponds to a A1C target of approximately 7% (53 mmol/mol).1
- Most people with type 1 and type 2 diabetes† , should spend at least 70% (approximately 17 hours) of the day within this glycemic range.1
- Each incremental 5% increase in TIR is associated with clinically significant benefits for people with type 1 or type 2 diabetes.1,11,12
- In addition to TIR, other CGM metrics can help guide diabetes management, such as Time Below Range (TBR), Time Above Range (TAR), mean glucose levels and glycemic variability.1,3
- TBR is the percentage of time spent below 3.9 mmol/L.1
- TAR is the percentage of time spent above 10.0 mmol/L.1
- Most people with diabetes† , are advised to spend less than 4% of their day below range (one hour)‡ and less than 25% of their day above range (six hours).§1
These clinical guidance recommendations and targets were put in place to help healthcare professionals interpret, report, and apply CGM data. This insight allows them to build individualized action plans to improve diabetes management and increase TIR for people with diabetes.1
* The International Consensus Report was endorsed following the 2019 ATTD congress by: American Diabetes Association, American Association of Clinical Endocrinologists, American Association of Diabetes Educators, European Association for the Study of Diabetes, Foundation of European Nurses in Diabetes, International Society for Pediatric and Adolescent Diabetes, JDRF and Pediatric Endocrine Society.
† For older and/or high-risk people with diabetes, the TIR target is lowered to >50% and TBR reduced to <1% at <3.9 mmol/L.1
‡ <1% of this time should be spent in the “very low” TBR of <3.0 mmol/L.1
§ <5% of this time should be spent in the “very high” TAR of >13.9 mmol/L.1
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