CGM Time in Range Predicts Arterial Stiffness Progression in Type 2 Diabetes

Cardiovascular disease remains the leading cause of death in people with type 2 diabetes, and arterial stiffness is an established early marker of cardiovascular risk. While HbA1c has long been the standard metric for glycemic control, it provides only an average blood sugar picture and may miss dangerous glucose fluctuations. Continuous glucose monitoring now allows more nuanced metrics — particularly time in range — to be tracked longitudinally.

This exploratory study drew from an ongoing prospective, multicenter observational cohort in Japan. A total of 348 adults with type 2 diabetes and no prior symptomatic cardiovascular disease underwent brachial-ankle pulse wave velocity measurements at baseline, 104 weeks, and 260 weeks. Participants were stratified by median baseline values of CGM-derived metrics and HbA1c, with arterial stiffness changes assessed using mixed-effects models adjusted for conventional atherosclerotic risk factors.

Arterial stiffness increased significantly over the study period, with baPWV rising a median of 60.1 cm/s by two years and 130.3 cm/s by five years. Participants with lower baseline TIR showed significantly greater increases in arterial stiffness over time compared to the higher TIR group. This interaction between TIR group and time remained significant after additional adjustment for HbA1c. Notably, glucose variability (coefficient of variation), other CGM metrics, and HbA1c itself were not independently associated with longitudinal baPWV changes.

These findings suggest that TIR offers prognostic information about vascular aging beyond what HbA1c provides, potentially supporting its use as a routine clinical target to reduce cardiovascular risk in type 2 diabetes.

Key caveats include the exploratory nature of the analysis, the exclusively Japanese study population limiting generalizability, and the fact that this summary is based on the abstract only, with full methodology details unavailable.