Acute kidney injury and progressive diabetic kidney disease: An epidemiological perspective

Purpose: Diabetic kidney disease (DKD) represents a unique subset of patients with chronic kidney disease (CKD). Acute kidney injury (AKI) is implicated in DKD progression; however, their interplay is not studied well. We studied risk factors for AKI and the effect of AKI on disease progression in a homogeneous group of patients with DKD. Patients and Methods: We conducted a retrospective open cohort study of patients with DKD at a single tertiary care centre between August 2016 – August 2019. Patients with a minimum follow-up of 2 years were included in the study. The incidence, etiology and risk factors for AKI were studied. The primary outcome studied was the effect of AKI on reduction in estimated glomerular filtration rate (eGFR) in DKD. Loss in eGFR by 50% and need for renal replacement therapy or reaching CKD stage V were studied as secondary outcomes. Results: Two hundred and ninety-two DKD patients meeting the study criteria with a follow-up of 29.57 (±4.3) months were included. The incidence of AKI was 31.1%. Sepsis was the most common etiology (61%). Proteinuria was an independent risk factor for AKI after adjusting for covariates (adjusted OR-1.158; 95% CI (1.018–1.316); p=0.025). In patients with AKI, median decline in eGFR was 10.29 mL/min/1.73m²/year (IQR-5.58– 13.84) which was significantly higher compared to patients with no AKI [eGFR 7.25 (IQR 5.06–11.38); p-0.014]. On subgroup analysis, sepsis-induced AKI (versus non-sepsis AKI; p<0.001) and higher AKI stage (stage 2/3 versus stage 1; p=0.019) were associated with a faster decline in eGFR. Conclusion: AKI is common in patients with DKD with sepsis being the most common etiology. AKI in diabetic kidney disease is associated with a faster decline in eGFR. Baseline proteinuria is an independent risk factor for AKI.