Acute kidney injury in children with chronic kidney disease is associated with faster decline in kidney function

Abstract

Background: This study aimed to investigate the association of acute kidney injury (AKI) with change in estimated glomerular filtration rate (eGFR) in children with advanced chronic kidney disease (CKD).

Methods: Single centre, retrospective longitudinal study including all prevalent children aged 1-18 years with nondialysis CKD stages 3-5. Variables associated with CKD were analysed for their potential effect on annualised eGFR change (ΔGFR/year) following multiple regression analysis. Composite end-point including 25% reduction in eGFR or progression to kidney replacement therapy was evaluated.

Results: Of 147 children, 116 had at least 1-year follow-up in a dedicated CKD clinic with mean age 7.3 ± 4.9 years with 91 (78.4%) and 77 (66.4%) with 2- and 3-year follow-up respectively. Mean eGFR at baseline was 29.8 ± 11.9 ml/min/1.73 m² with 79 (68%) boys and 82 (71%) with congenital abnormalities of kidneys and urinary tract (CAKUT). Thirty-nine (33.6%) had at least one episode of AKI. Mean ΔGFR/year for all patients was - 1.08 ± 5.64 ml/min/1.73 m² but reduced significantly from 2.03 ± 5.82 to - 3.99 ± 5.78 ml/min/1.73 m² from youngest to oldest age tertiles (P < 0.001). There was a significant difference in primary kidney disease (PKD) (77% versus 59%, with CAKUT, P = 0.048) but no difference in AKI incidence (37% versus 31%, P = 0.85) between age tertiles. Multiple regression analysis identified age (β = - 0.53, P < 0.001) and AKI (β = - 3.2, P = 0.001) as independent predictors of ΔGFR/year. 48.7% versus 22.1% with and without AKI reached composite end-point (P = 0.01).

Conclusions: We report AKI in established CKD as a predictor of accelerated kidney disease progression and highlight this as an additional modifiable risk factor to reduce progression of kidney dysfunction. Graphical abstract.

Keywords: Acute kidney injury; Children; Chronic kidney disease; Hypertension; Progression; Proteinuria; Risk factor.

Fig. 1

Baseline CKD stage distribution in each age tertile with tertile 1 including the youngest children. CKD chronic kidney disease

Fig. 2

Changes in annual eGFR (ml/min/1.73 m²) between different age tertiles in those with AKI and those with no AKI episodes. A two-way ANOVA was conducted to examine the effect of age tertile and acute kidney injury incidence on ∆GFR/year. eGFR estimated glomerular filtration rate, AKI acute kidney injury

Fig. 3

Kaplan–Meier plot showing time to composite end-point of 25% reduction in GFR or progression to kidney replacement therapy in those with AKI versus those with no AKI. eGFR estimated glomerular filtration rate, AKI acute kidney injury