HbA1c trajectory and cardiovascular outcomes: an analysis of data from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study

BACKGROUND: We investigated the associations between glycated hemoglobin (HbA1c) trajectories and cardiovascular outcomes using data from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study. METHODS: We used HbA1c values within the first 2 years of treatment for modeling with a latent class growth model. Groups of HbA1c trajectories were modeled separately in the standard (group 1–group 4) and intensive (group 5–group 8) treatment arms. The primary outcome in the ACCORD study was a composite of non-fatal myocardial infarction, non-fatal stroke, or death from cardiovascular causes. Effects of HbA1c trajectories on cardiovascular outcomes were analyzed using a Cox-proportional hazard model. RESULTS: Baseline HbA1c levels for the eight trajectories (group 1–group 8) were 7.8 ± 0.8, 8.2 ± 0.9, 9.3 ± 1.1, 9.6 ± 1.2, 7.8 ± 0.7, 10.1 ± 0.8, 8.3 ± 0.7, and 9.5 ± 1.1%, respectively. The respective values after 2 years of treatment were 7.0 ± 0.6, 7.7 ± 0.7, 8.5 ± 0.9, 10.3 ± 1.3, 6.2 ± 0.4, 6.5 ± 0.6, 7.2 ± 0.6, and 8.5 ± 1.1%. After a median follow-up of 4.8 years, group 5 and group 6 had similar outcomes compared with group 1 (reference group). In contrast, group 3, group 4, and group 8 had higher risks of the primary composite outcome compared with group 1. CONCLUSION: HbA1c trajectory was associated with cardiovascular outcomes in type 2 diabetes patients with high cardiovascular risk.