The relationship between repeated measurements of HbA1c and risk of coronary events among the common haptoglobin phenotype groups: the Action for Health in Diabetes (Look AHEAD) study

Abstract

Abstract Background In the ACCORD study, participants with the haptoglobin (Hp) 2–2 phenotype and glycated hemoglobin (HbA1c) ≥ 8.0% had a higher risk of coronary artery disease (CAD) compared to those with HbA1c 7.0–7.9%. However, this association was not observed in participants without the Hp2-2 phenotype. The optimal glycemic target for CAD prevention for the Hp phenotypes remains uncertain and may vary based on demographic and clinical factors. Objective To investigate how reaching clinically relevant HbA1c targets relates to the risk of CAD in different Hp phenotype groups among a diverse cohort of individuals with T2DM (the Look AHEAD study, HbA1c ≤ 11% at baseline). Methods Cox regression models with time-varying covariables were used to quantify the association between time-varying achieved HbA1c ( 10 years (0.58, 0.35–0.95). HbA1c ≥ 8.0% was associated with CAD risk only among participants with the Hp2-2 phenotype who had a history of CVD (1.79, 1.00-3.20). No associations were found between the other HbA1c targets and CAD risk when participants with the Hp2-2 phenotype were grouped together or divided into subgroups. Conclusion The differences in our results compared to our previous findings may be due to variations in the study populations and factors associated with weight loss, making it difficult to draw definitive conclusions. Our current findings should be considered in the context of hypothesis generation, and ideally, will encourage additional research in this field.

Keywords

• Coronary artery disease
• Epidemiology
• Genetic association
• Glycated hemoglobin
• Haptoglobin phenotype
• Type 2 diabetes mellitus