HbA1c metrics may predict CAC and CVD events in type 1 diabetes patients

"Even after adjustment for numerous CVD risk factors, these associations with CVD events persisted for mean HbA1c, baseline HbA1c, and time-varying HbA1c," the researchers wrote in their study published in The Journal of Clinical Endocrinology & Metabolism.

Interventions that decrease mean glucose have lowered macro- and microvascular complication rates in type 1 diabetes (T1D). However, there is a difference in CV risk between type 1 diabetes patients and the general population, indicating that factors beyond HbA1c normalization drive cardiovascular outcomes.

Against the above background, William B Horton from the University of Virginia School of Medicine in Charlottesville, VA, and colleagues aimed to determine whether various HbA1c metrics predict anatomic CVD risk factors and events in people with type 1 diabetes.

For this purpose, the researchers used linear regression to analyze the relationship between various HbA1c metrics and anatomic CVD risk factors. Cox regression was used to model their relationship to incident CVD events in the CACTI Study.

The study revealed the following findings:

• In linear regression models adjusted for age, sex, and T1D duration, baseline Hba1c (b = 0.3998), mean HbA1c (b = 0.5385), and HbA1c standard deviation (SD) (b = 1.1521) were each positively associated with square root transformed coronary artery calcium volume.
• Only mean HbA1c (b = 1.659) was positively associated with pericardial adipose tissue volume.
• In survival models adjusted for age, sex, and T1D duration, baseline HbA1c (HR: 1.471), mean HbA1c (HR: 1.850), time-varying HbA1c (HR: 1.500), and HbA1c SD (HR: 1.665) each independently predicted CVD events over 14.3 ± 5.2 person-years of follow-up.

"We found that several hemoglobin A1C positively correlated with CAC volume and independently predicted CVD events in the CACTI T1D cohort," the researchers wrote. "These associations with cardiovascular events persisted for mean HbA1c, baseline HbA1c, and time-varying HbA1c even after adjusting for numerous CVD risk factors."

Reference:

William B Horton, MD, MSc, FACP, Janet K Snell-Bergeon, PhD, MPH, HbA1c Variability Metrics Predict Coronary Artery Calcium and Cardiovascular Events in Type 1 Diabetes: the CACTI Study, The Journal of Clinical Endocrinology & Metabolism, 2023;, dgad019, https://doi.org/10.1210/clinem/dgad019