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High HbA1c Variability and Risk of MACE

Diabetes Care; ePub 2018 Oct 23; Ghouse, et al

High glycated hemoglobin A1c (HbA1c) variability was associated with increased risks of major adverse cardiovascular events (MACE) and all-cause mortality in a primary care population free of diabetes and cardiovascular disease (CVD), a new study found. Patients with 3 annual HbA1c measurements within normal range were included. Associations between HbA1c variability and outcome were analyzed using Cox regression, adjusted for traditional risk factors, intercept, and trends, and reported as hazard ratio per SD increase in variability (HRSD). Among the findings:

  • 6,756 individuals were included in the study.
  • 996 individuals developed MACE, 856 died, and 1,267 developed type 2 diabetes (T2D) during median follow-up of 6.3 years.
  • There was a significant association between increasing HbA1c variability and incident MACE (HRSD 1.09) and all-cause mortality (HRSD 1.00).
  • Clinically relevant differences were found across several age, sex, and comorbidity subgroups in calculating 5-year absolute risks of MACE and all-cause mortality.


Ghouse J, Skov MW, Kanters JK, et al. Visit-to-visit variability of hemoglobin A1c in people without diabetes and risk of major adverse cardiovascular events and all-cause mortality. [Published online ahead of print October 23, 2018]. Diabetes Care. doi:10.2337/dc18-1396.