A hemoglobin A1c (HbA1c) test measures a person’s average blood sugar (glucose) level during the past 2 to 3 months, and is an important tool for screening, diagnosing, and monitoring diabetes. Growing evidence suggests that HbA1c can also be a marker for risk of cardiovascular disease (CVD) in individuals without diabetes, however, whether there are variances between males and females is not well established. In a recently published study in the Journal of the American Heart Association, researchers sought to examine the association between HbA1c and the development of CVD in males and females without diabetes or CVD.
This retrospective study included 608,474 adults between the age of 40 and 79 from Alberta, Canada who did not have diabetes or CVD at study inception. Males and females were divided into groups based on 0.5% increments of HbA1c (<5.0%, 5.0% to 5.4%, 5.5% to 5.9%, 6.0% to 6.4%, and ≥ 6.5%) during a 3-year enrollment period starting in 2013. The study’s primary outcome of CVD hospitalization and secondary outcome of combined CVD hospitalization/mortality were analyzed during a 5-year follow-up period ending in 2021.
The researchers found that among males, an increased risk of CVD was linked to both normal levels of HbA1c (5.5%-5.9%) and higher levels of HbA1c indicative of prediabetes (6.0%–6.4%), and diabetes (≥6.5%), whereas, an increased risk of CVD for females was limited to those with HbA1c levels ≥6.0%. These results demonstrate that HbA1c is an important marker for CVD, and highlight the need for enhanced CVD risk profiles for all glucose levels, especially among male patients. Given the link between increased CVD risk and HbA1c levels ≥6.0% in both sexes, the authors also emphasize the critical role of surveillance and early intervention in patients with prediabetes.
This research was undertaken as part of the The Real‐World Evidence on the Association Between DIabetes and Sex on Cardiovascular Event Rates (REDISCOVER) study, which utilizes the rich population-health data available in Alberta to provide new insights into the relationship of sex and diabetes on CVD outcomes. This paper was led by Sonia Butalia, MD (University of Calgary) in collaboration with the CVC’s Padma Kaul, PhD (senior author), Douglas Dover, Phd, and Luan Manh Chu, PhD, as well as Roseanne Yeung, MD, Darren Lau, MD, Dean Eurich, PhD, and Peter Senior, MD (University of Alberta).
