Continuous Glucose Monitoring (CGM) has become an essential tool for managing diabetes, particularly in youth with type 1 diabetes (T1D). This study investigates the relationship between Time-in-Range (TIR) and HbA1c levels, focusing on the impact of CGM sensor wear-time.
Background
TIR is a critical glycemic metric, with a TIR greater than 70% associated with lower HbA1c levels. However, the reliability of TIR data when CGM wear-time is less than optimal remains less understood. This research aims to clarify the association between TIR and HbA1c in youth with varying CGM wear-times.
Method
The study included 60 youth diagnosed with T1D, categorized based on their CGM wear-time into two groups: those with ≥70% wear-time and those with <70% wear-time. Pearson correlations between TIR and HbA1c were calculated for each group, and the strength of these correlations was compared using a Fisher r-to-z transformation.
Results
The findings revealed significant correlations between TIR and HbA1c in both groups. For the group with ≥70% CGM wear-time, the correlation coefficient was r = -0.800 (p < .001), indicating a strong inverse relationship. In contrast, the group with <70% wear-time showed a weaker correlation of r = -0.404 (p < .001). The comparison of these correlations yielded a z-score of 3.15 (p = .0016), demonstrating that the association was significantly stronger in the ≥70% wear-time group.
Conclusion
While the correlation between TIR and HbA1c was weaker in individuals with <70% CGM wear-time, the statistical significance suggests that there may still be utility in utilizing lower wear-time data when necessary. This finding emphasizes the importance of CGM wear-time in accurately assessing glycemic control in youth with T1D.
What this study does not show
This study does not establish a causal relationship between CGM wear-time and HbA1c levels, nor does it assess the clinical outcomes of interventions based on TIR data.
Evidence scorecard
- Analytic validity: Established
- Clinical validity: Established
- Clinical utility: Not established
The evidence class is primary_research, and the human status is unclassified.