Continuous Glucose Monitors (CGMs) have become essential tools for managing diabetes, particularly for tracking glycemic metrics like time-in-range (TIR). The TIR metric is increasingly recognized for its association with lower HbA1c levels, a key indicator of long-term glucose control. This study, published in the Journal of Diabetes and Its Complications, investigates how CGM wear-time impacts the relationship between TIR and HbA1c in youth with type 1 diabetes (T1D).
Study Overview
The research included 60 youth diagnosed with T1D, categorized based on their CGM wear-time: those with ≥70% wear-time and those with <70% wear-time. The primary aim was to assess the correlation between TIR and HbA1c within these two groups.
Methodology
Researchers calculated Pearson correlations between TIR and HbA1c for each wear-time group. They then compared these correlations using a Fisher r-to-z transformation to determine if the strength of the association differed significantly between the two groups.
Results
Findings revealed significant correlations in both groups. For the ≥70% wear-time group, the correlation coefficient was r = -0.800 (p < .001), indicating a strong inverse relationship between TIR and HbA1c. Conversely, the <70% wear-time group showed a weaker correlation of r = -0.404 (p < .001). The analysis confirmed that the association was significantly stronger in the ≥70% group (z = 3.15, p = .0016).
Conclusion
While the correlation between TIR and HbA1c was weaker in individuals with <70% CGM wear-time, the statistical significance suggests that lower wear-time data may still provide useful insights when necessary. This finding is particularly relevant for clinicians and patients who may face challenges in maintaining consistent CGM usage.
What this study does not show
This study does not establish a causal relationship between CGM wear-time and HbA1c levels, nor does it provide evidence on the clinical outcomes of relying on lower wear-time data.
Evidence scorecard
- Analytic validity: Established
- Clinical validity: Established
- Clinical utility: Not established
The evidence class is primary_research with human status unclassified.