Time in Range and Adverse Outcomes in Type 2 Diabetes: A Quantitative Synthesis

Area of Science:

• Endocrinology
• Metabolic Diseases
• Clinical Research

Background:

• Type 2 diabetes mellitus (T2DM) management requires effective prognostic indicators.
• Glucose monitoring, including continuous glucose monitoring (CGM), flash glucose monitoring (FGM), and fingertip capillary glucose monitoring (FCGM), provides valuable data.
• Time in range (TIR) is a key metric derived from glucose monitoring.

Purpose of the Study:

• To quantify the prognostic value of TIR from various glucose monitoring methods for adverse clinical outcomes in T2DM patients.
• To assess the association between TIR and risks of mortality and micro/macrovascular complications.

Main Methods:

• Systematic literature search of PubMed, Embase, and CENTRAL from 2017 to November 2025.
• Inclusion of 24 observational studies with 35,916 participants.
• Dose-response meta-analyses using random-effects models and the GRADE framework for evidence certainty.

Main Results:

• A 10% increment in TIR was significantly associated with reduced risks of all-cause mortality (OR=0.88), vision-threatening diabetic retinopathy (OR=0.93), diabetic retinopathy (OR=0.92), lower extremity atherosclerotic disease (OR=0.86), diabetic peripheral neuropathy (OR=0.77), and cardiovascular autonomic neuropathy (OR=0.81).
• Associations for albuminuria and amputation did not reach statistical significance.
• High certainty of evidence supports these findings.

Conclusions:

• Each 10% increase in TIR is consistently linked to a lower risk of mortality and various micro- and macrovascular complications in T2DM.
• TIR serves as a reliable prognostic indicator in diabetes management.
• Improving TIR should be an actionable therapeutic target for patients with T2DM.