The impact of diabetes mellitus on acute kidney injury after coronary artery bypass grafting

BACKGROUND: Diabetes mellitus(DM) is an indicator affects postoperative mortality and morbidity after coronary artery bypass grafting (CABG). Acute kidney injury (AKI) is one of the frequent postoperative complications after CABG. This multi-centre register study designed to investigate the impact of DM on postoperative AKI in primary isolated CABG patients. METHODS: We included all patients (n = 4325) from Jiangsu Province CABG register who underwent primary isolated CABG from September 2017 to August 2019. The patients were divided into 3 groups: No-DM group(n = 3067), DM-oral group (DM with oral hypoglycemic agents, n = 706) and DM-insulin group (DM with insulin treatment, n = 552). The development and severity of AKI were based on Acute Kidney Injury Network (AKIN) criteria. RESULTS: There were totally 338, 108 and 145 patients developed AKI in No-DM, DM-oral and DM-insulin group respectively. Comparing with No-DM group, DM-oral group had a higher rate of AKI(χ(2) = 10.071, p = 0.002), DM-insulin group had a higher rate(χ(2) = 94.042, p<0.001) and severity of AKI(χ(2) = 10.649, p = 0.005). The adjusted odds ratio for AKI was 1.26 (95% CI 1.03–1.57) in DM-oral group and 3.92 (95% CI 3.27–5.16) in DM-insulin group, in comparison with No-DM group. CONCLUSIONS: Independent of baseline renal function or cardiac function, DM was associated with an increased risk of AKI after CABG, especially in patients with insulin treatment, who also had a higher severity of AKI.