Type 1 and type 2 diabetes mellitus and risk of acute kidney injury after coronary artery bypass grafting

Background Our objective was to investigate the association between type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and acute kidney injury (AKI) in patients who underwent coronary artery bypass grafting (CABG). Methods We included all patients (n = 36,106) from the SWEDEHEART register who underwent primary isolated CABG in Sweden from 2003 to 2013. Information on type of diabetes was retrieved from the Swedish National Diabetes Register. Acute kidney injury was defined as an absolute increase by 0.3 mg/dL (26 μmol/L) or a relative increase by at least 50% in postoperative serum creatinine compared with preoperative levels. Odds ratios with 95% CIs for AKI in patients with T1DM and T2DM were compared with those patients without diabetes using logistic regression. Results In total, there were 457 patients (1.3%) with T1DM and 5124 (14%) with T2DM. Among patients with T1DM and T2DM, 145 (32%) and 1037 (20%), respectively, developed AKI, compared with 4017 (13%) in patients without diabetes. The adjusted odds ratio for AKI was 4.89 (95% CI 3.82-6.25) in patients with T1DM and 1.27 (95% CI 1.16-1.40) in patients with T2DM, in comparison with patients without diabetes. Conclusions Both T1DM and T2DM were associated with an increased risk of AKI after CABG. The risk was markedly higher in patients with T1DM than in those with T2DM and was independent of preoperative renal function.