Mortality trends involving chronic kidney disease and electrolyte and acid-base disorders in the United States, 1999-2023: a CDC WONDER analysis.

BACKGROUND: Chronic kidney disease (CKD) is a growing global health burden, often complicated by electrolyte and acid-base disorders that exacerbate morbidity and mortality. Despite recognition of CKD-related cardiovascular outcomes, mortality patterns involving metabolic complications remain underexplored. METHODS: Using CDC WONDER Multiple Cause-of-Death data (1999-2023), we identified adult deaths (≥25 years) involving CKD (ICD-10 code N18) and electrolyte and acid-base disorders (ICD-10 codes E87.0-E87.8). Age-adjusted mortality rates (AAMRs) were calculated per 100 000 population, stratified by sex, race/ethnicity, census region, and urbanization. Temporal trends were assessed using Joinpoint regression. RESULTS: Between 1999 and 2023, 75 149 deaths occurred among individuals with both CKD and electrolyte/acid-base disorders (overall AAMR, 1.35). Mortality remained relatively stable, with a non-significant downward trend until 2008, and then rose sharply (APC, 6.54%; 95% CI, 5.33-7.77), peaking during the COVID-19 pandemic. Men had consistently higher AAMRs than women (1.63 vs 1.14). Non-Hispanic Black individuals had the highest burden (AAMR, 3.01), nearly threefold higher than that of non-Hispanic Whites. Geographic disparities were also evident, with the South and rural counties experiencing higher and progressively increasing mortality rates. CONCLUSIONS: Mortality co-involving CKD and electrolyte and acid-base disorders has more than doubled in the U.S. since 2008, with widening disparities by sex, race/ethnicity, and geography. These findings highlight the growing contribution of metabolic complications to CKD-related mortality and underscore the need for earlier detection and management of electrolyte and acid-base disturbances alongside equity-focused interventions for high-risk populations.