Methods: We conducted a post hoc analysis using two datasets derived from JNR-IgAN 2019 (n=1065) and J-IGACS 2023 (n=941).Patients in each cohort were stratified according to corticosteroid use within the first year of follow-up: corticosteroid users (CS) and non-users (non-CS), with the latter serving as the reference group.Overlap weighting was applied to each dataset to adjust for baseline imbalances.The primary outcome was the total number of adverse events, including infections, new-onset diabetes mellitus, cerebrovascular, cardiovascular, and other systemic complications.Secondary outcomes comprised individual components of the primary outcome.Incidence risk ratios (IRRs) were estimated using negative binomial regression for each cohort and subsequently pooled.Key baseline variables were identified via multivariable analysis and their associations with corticosteroidrelated IRRs were explored using restricted cubic spline modeling.Results: The number of primary outcome events was 95 in JNR-IgAN 2019 and 103 in J-IGACS 2023.The pooled IRR for the primary outcome (CS vs. non-CS) was 3.25 (95% CI: 0.68-15.58).In both the JNR-IgAN 2019 and J-IGACS 2023 cohorts, IRRs increased steeply and exhibited a non-linear association with advancing age.Regarding secondary outcomes, corticosteroid use was associated with elevated risks of infection (pooled IRR: 6.99, 95% CI: 0.39-126.1),new-onset diabetes mellitus (pooled IRR: 26.7, 95% CI: 1.36-526.3),and composite events including death, malignancy, and orthopedic disorders (pooled IRR: 8.01, 95% CI: 0.99-64.7).Conversely, the risk of cerebrovascular, cardiovascular, and vascular events was significantly lower in corticosteroid-treated patients (pooled IRR: 0.02, 95% CI: 0.00-0.26). Conclusion:This study informs clinical practice by emphasizing the need for individualized corticosteroid use in IgAN.Although corticosteroids may offer renal benefits, their association with increased risks of infection, new-onset diabetes, and other systemic complicationsparticularly in older patients-calls for careful patient selection and monitoring.Age-dependent escalation of adverse events suggests that immunosuppressive strategies should be tailored based on patient vulnerability, not applied uniformly.The unexpected reduction in vascular-related events warrants further investigation and may help refine future risk-benefit assessments.I have no potential conflict of interest to disclose.I did not use generative AI and AI-assisted technologies in the writing process.
Krishnasamy et al. (Wed,) studied this question.