Adults with long-standing type 1 diabetes showed associations between continuous glucose monitoring (CGM) metrics and cardiovascular autonomic neuropathy (CAN). Findings were presented at the European Association for the Study of Diabetes Conference 2025.

The analysis included 751 participants from the DCCT/EDIC study. Standard resting electrocardiograms were obtained, and blinded CGM was performed for an average of 11.9 days. CAN was defined by indices of heart rate variability (standard deviation of R-R intervals and root mean square of successive differences).

Participants with CAN had higher HbA1c (7.9% vs 7.6%), higher mean sensor glucose (172.3 vs 162.0 mg/dL), and spent more time in hyperglycemia (>180 mg/dL: 40.4% vs 35.3%, >250 mg/dL: 16.8% vs 13.9%). They had lower time in target range (51.1% vs 54.2%) and less time in hypoglycemia (<54 mg/dL: 3.9% vs 5.0%).
Age-adjusted models showed significant associations between CGM metrics and CAN. However, these were fully attenuated after adjustment for current HbA1c. HbA1c remained independently associated with CAN.

Short-term CGM metrics reflected glycemic patterns linked to autonomic neuropathy, but longer-duration monitoring may be required to improve predictive accuracy.