ApoB/ApoA-I ratio and all-cause mortality in maintenance hemodialysis: a cohort study

Traditional lipid markers have limited and inconsistent prognostic value in maintenance hemodialysis (MHD), a phenomenon often described as the lipid paradox. We evaluated whether lipid and apolipoprotein-related markers, particularly the ApoB/ApoA-I ratio, were associated with mortality in MHD patients. This single-center retrospective cohort study included 409 MHD patients. Lipid and apolipoprotein-related markers were analyzed as standardized continuous variables. Cox regression was used for all-cause mortality, and cause-specific Cox and Fine–Gray models were used for cardiovascular mortality. During a median follow-up of 55.7 months, 148 all-cause deaths occurred, including 61 cardiovascular deaths. ApoB/ApoA-I was not associated with all-cause mortality in the unadjusted model, but was independently associated with all-cause mortality in Model 3 (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.05–1.44; p = 0.012). The association was similar in sensitivity analyses. ApoB/ApoA-I was not significantly associated with cardiovascular mortality in exploratory Fine–Gray regression (subdistribution hazard ratio [SHR] 1.12, 95% CI 0.89–1.43; p = 0.337) and did not improve discrimination beyond the base clinical model. These findings suggest that ApoB/ApoA-I may contribute to risk characterization and etiologic understanding in MHD, but do not support its use as a stand-alone clinical prediction marker.