Glycemic control and renal function decline in patients with chronic coronary syndrome: A multicenter cohort study

Abstract Aims/Introduction Diabetes mellitus significantly contributes to renal complications, especially in patients with coronary artery disease (CAD). Effective glycemic control is important; however, the ideal hemoglobin A1c (HbA1c) targets for this population remain uncertain. This observational cohort study aimed to identify appropriate HbA1c targets for patients with diabetes and chronic coronary syndrome. Materials and Methods This study included 1,223 patients with chronic coronary syndrome, which were identified from a multicenter cohort registry study. Among them, there were 698 patients with diabetes. Patients were categorized based on their diabetes status and HbA1c levels. The primary outcome was the incidence of minor and major renal events, defined as a decline in the estimated glomerular filtration rate (eGFR) of more than 25% and 50%. Cox proportional hazards regression models were employed to assess the impact of glycemic control on renal function. Results Over a mean follow‐up of 3.2 ± 2.0 years, the highest incidences of minor renal events were noted in the group with diabetes and HbA1c ≥ 7.5% (25.1%), followed by diabetes and HbA1c < 6.5% (21.2%). Compared to the group without diabetes, the adjusted hazard ratios (95% confidence intervals) for minor renal events in the groups with diabetes and HbA1c ≥ 7.5%, HbA1c 7.0–7.4%, HbA1c 6.5–6.9%, and HbA1c < 6.5% were 3.06 (2.08–4.50), 1.75 (1.08–2.84), 1.32 (0.81–2.23), and 2.59 (1.58–4.24), respectively. Conclusions Achieving HbA1c of 6.5 to 6.9% is associated with a reduced risk of renal complications in patients with diabetes and chronic coronary syndrome.