Myelodysplastic syndromes and risk of kidney function decline: findings from a nationwide Japanese cohort study

Abstract Background Myelodysplastic syndromes(MDSs) have been known to be associated with various forms of kidney disease; however, whether they predispose to a longitudinal decrease in kidney function in the general population is unknown. This study aimed to investigate the association between MDSs and the risk of kidney function decline using a large-scale population-based cohort. Methods We retrospectively analysed nationwide administrative claims and health checkup data collected between April 2014 and August 2024. MDSs were identified using International Classification of Diseases, 10th Revision codes. Individuals were categorized into two groups according to the presence of MDSs. The primary outcome was a composite kidney outcome, defined as incident end-stage kidney disease, initiation of kidney replacement therapy or a ≥30% decline in estimated glomerular filtration rate. Results Among 1 659 421 individuals {median age 68 years [interquartile range (IQR) 61–72]; 41.9% male}, MDSs were identified in 901 individuals (0.05%). During a median follow-up of 1092 days (IQR 631–1520), 33 335 individuals experienced the composite kidney outcome. Cumulative incidence curves demonstrated a higher incidence of kidney function decline in individuals with MDSs compared with those without MDSs (P < .001, logrank test). In multivariable Cox regression analysis, the presence of MDSs was independently associated with an increased risk of kidney function decline [hazard ratio 2.28 (95% confidence interval 1.66–3.13)]. Conclusions In this large-scale nationwide cohort, MDSs were significantly associated with an increased risk of kidney function decline, positioning MDSs as a clinically relevant kidney risk condition and supporting closer kidney monitoring in this population.