Serum ceramides predict all-cause and cardiovascular mortality in Chinese incident hemodialysis patients: a retrospective cohort study

Background: This study explored serum ceramide (Cer) levels' association with all-cause and cardiovascular disease (CVD) mortality in Chinese incident hemodialysis (HD) patients. Methods: This retrospective cohort study included 253 adults enrolled between January 2015 and December 2017. Cox proportional hazard and Fine-Gray subdistribution hazard models were used to assess associations between serum Cer quintiles and clinical outcomes. Restricted cubic spline (RCS) regression was used to explore nonlinear relationships, with sensitivity analysis assessing robustness. Results: Over a median follow-up period of 88 months, 122 deaths (48.2%) occurred, with 85 (33.6%) attributed to cardiovascular- related issues. Higher Cer (24:1)/Cer (24:0) ratio was associated with increased all-cause mortality and CVD mortality. Per 1-standard deviation (SD) increment in Cer (24:1) was correlated with elevated CVD mortality. The Fine-Gray model further demonstrated that higher Cer (24:1)/Cer (24:0) ratio and per 1-SD rise in Cer (24:1) were both significantly associated with CVD mortality. The RCS regression model indicated that all-cause mortality risk increased linearly with an elevated Cer (24:1)/Cer (24:0) ratio and Cer (24:1) level, while the risk of CVD mortality increased linearly with an elevated Cer (24:1)/Cer (24:0) ratio. Furthermore, Cer (24:1) demonstrates a U-shaped trend with CVD mortality; however, this non-linear relationship did not reach statistical significance (all p for nonlinearity, >0.05). The findings were robust in sensitivity analyses. Conclusion: Serum Cer (24:1)/Cer (24:0) ratio and Cer (24:1) levels were positively associated with increased all-cause and CVD mortality in HD patients, suggesting serum ceramides may be a risk factor reducing longevity for HD patients.