Can Hb glycation index substitute for HbA1c?

Takeaway

• In patients with type 2 diabetes mellitus (T2DM) but without prior cardiovascular disease, higher Hb glycation index (HGI) is associated with an increased risk for cardiovascular events.
• Similar association was observed between HbA1c and risk for cardiovascular disease.
• Since HbA1c is comparable to HGI as a cardiovascular risk factor and obtaining/ interpreting HGI is complicated, its application in clinical setting may be limited.

Why this matters

• Factors affecting Hb glycosylation influence relation between blood glucose and HbA1c.
• HGI, difference between observed and predicted HbA1c could be a way to address this discordance.

Study design

• Study evaluated 1910 patients with T2DM from Second Manifestations of Arterial Disease (SMART) study.
• Primary outcome: major vascular event (a composite of myocardial infarction, stroke, retinal infarction, terminal heart failure, sudden death and vascular mortality).
• Funding: None.

Key results

• During an average follow-up period of 9.6 years, 19.9% patients experienced a cardiovascular event.
• HGI was significantly associated with composite of cardiovascular events in patients without cardiovascular disease (HR, 1.29; 95% CI, 1.06-1.57) but not in patients with previous cardiovascular disease (HR, 0.96; 95% CI, 0.86-1.08).
• Similarly, HbA1c was associated with higher cardiovascular events in patients without cardiovascular disease (HR, 1.23; 95% CI, 1.04-1.45) but not in patients with cardiovascular disease (HR, 1.02; 95% CI, 0.92-1.12).

Limitations

• Single-center study.