A comparative study on the risk of acute kidney injury in children induced by iso-osmolarity and low-osmolarity contrast media

BACKGROUND: To compare the risk of contrast-associated acute kidney injury (CA-AKI) caused by iso-osmolarity contrast media (IOCM) and low-osmolarity contrast media (LOCM) in pediatric patients. METHODS: A retrospective cohort exposed to contrast-enhanced CT was constructed based on the inpatients from Beijing Children's Hospital (2015-2020). The patients were divided into IOCM and LOCM exposure. AKI was defined by the pediatric version of Kidney Disease: Improving Global Outcomes (KDIGO, pKDIGO) criteria. After adjusting baseline differences with inverse probability of treatment weighting (IPTW), log-binomial regression was conducted to estimate the risk ratios (RR) and 95% confidence interval (CI) of AKI between the IOCM and LOCM groups. Subgroup analyses were performed by age (< 2 vs. ≥2 years), ICU status, CT scan site, and sex. RESULTS: Of 6081 pediatric patients exposed to CT enhanced scans, 1004 children were eligible for inclusion and exclusion criteria, in which there were 545 (54.3%) and 459 (45.7%) patients in the IOCM and LOCM groups, respectively. The unadjusted incidence of AKI in the IOCM (12.1%) was higher than that in LOCM (6.1%). However, the adjusted relative risk (aRR) indicated a significantly lower risk of CA-AKI with IOCM compared to LOCM (aRR: 0.54, 95% CI: 0.40-0.73). CONCLUSIONS: In the pediatric cohort, IOCM was associated with a significantly lower risk of CA-AKI compared to LOCM. This association was consistently observed across key subgroups, such as age, sex, and ICU status.