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Positioning time in range in diabetes management

  • Andrew AdvaniEmail author


Recent upswings in the use of continuous glucose monitoring (CGM) technologies have given people with diabetes and healthcare professionals unprecedented access to a range of new indicators of glucose control. Some of these metrics are useful research tools and others have been welcomed by patient groups for providing insights into the quality of glucose control not captured by conventional laboratory testing. Among the latter, time in range (TIR) is an intuitive metric that denotes the proportion of time that a person’s glucose level is within a desired target range (usually 3.9–10.0 mmol/l [3.5–7.8 mmol/l in pregnancy]). For individuals choosing to use CGM technology, TIR is now often part of the expected conversation between patient and healthcare professional, and consensus recommendations have recently been produced to facilitate the adoption of standardised TIR targets. At a regulatory level, emerging evidence linking TIR to risk of complications may see TIR being more widely accepted as a valid endpoint in future clinical trials. However, given the skewed distribution of possible glucose values outside of the target range, TIR (on its own) is a poor indicator of the frequency or severity of hypoglycaemia. Here, the state-of-the-art linking TIR with complications risk in diabetes and the inverse association between TIR and HbA1c are reviewed. Moreover, the importance of including the amount and severity of time below range (TBR) in any discussions around TIR and, by inference, time above range (TAR) is discussed. This review also summarises recent guidance in setting ‘time in ranges’ goals for individuals with diabetes who wish to make use of these metrics. For most people with type 1 or type 2 diabetes, a TIR >70%, a TBR <3.9 mmol/l of <4%, and a TBR <3.0 mmol/l of <1% are recommended targets, with less stringent targets for older or high-risk individuals and for those under 25 years of age. As always though, glycaemic targets should be individualised and rarely is that more applicable than in the personal use of CGM and the data it provides.


CGM Diabetes complications HbA1c Hyperglycaemia Hypoglycaemia Review Time below range Time in range 



Continuous glucose monitoring (or continuous glucose monitor)


Continuous subcutaneous insulin infusion


Multiple Daily Injections and Continuous Glucose Monitoring in Diabetes (study)


Glucose management indicator


Intermittently scanned continuous glucose monitor


Mean absolute relative difference


Patient-reported outcome


Real-time continuous glucose monitor


Self-monitoring of blood glucose


Time above range


Time below range


Time in range


Contribution statement

The author researched and wrote the article.


AA is a recipient of a Diabetes Investigator Award from Diabetes Canada. Research in the Advani Lab is supported by grants from the Canadian Institutes of Health Research, the RDV Foundation, the Heart and Stroke Foundation of Canada and the Kidney Foundation of Canada.

Duality of interest

AA has received research support through his institution from Boehringer Ingelheim and AstraZeneca and an unrestricted educational grant from Eli Lilly and has served on advisory boards for Dexcom, Abbott, Eli Lilly/Boehringer Ingelheim and Novo Nordisk.

Supplementary material

125_2019_5027_MOESM1_ESM.pptx (640 kb)
Slideset of figures (PPTX 640 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge InstituteSt Michael’s HospitalTorontoCanada

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