Associations of dietary fiber intake with all-cause and cardiovascular mortality among maintenance hemodialysis patients: a retrospective cohort study

To determine the association between dietary fiber intake (DFI) and all-cause mortality and cardiovascular mortality in Chinese maintenance hemodialysis (MHD) patients, considering fiber types and sources. Therefore, adjusted Cox regression analyses were utilized to assess the correlation between quartiles of DFI and mortality. Restricted cubic spline (RCS) regression was employed to investigate the nonlinear relationship between the total cereal fiber and mortality. Subgroup and sensitivity analysis was performed to examine the robustness. Among 742 patients (median follow-up: 30.47 months), 210 deaths (28.30%) occurred, including 149 (20.08%) cardiovascular-related deaths. Higher total cereal fiber intake correlated with reduced all-cause mortality [HR (hazard ratio) quartile 4 (Q4) vs. quartile 1 (Q1)=0.58, 95% CI: 0.36-0.93] and cardiovascular mortality (HR Q4 vs. Q1=0.53, 95% CI=0.30-0.95). Apart from fruit fiber as well as bean fiber for all-cause mortality and soluble fruit fiber for cardiovascular mortality, a similar association was observed for fiber from other dietary sources, albeit without statistical significance. Furthermore, each standard deviation increase in total cereal fiber intake lowered all-cause mortality risk (HR=0.82, 95% CI: 0.69-0.98). The findings were robust in all the subgroup and sensitivity analyses. Additionally, the RCS regression model indicated linear inverse associations between total cereal fiber and mortality risks (all pnonlinear>.05). In conclusion, total cereal fiber intake was inversely associated with reduced all-cause and cardiovascular mortality in MHD patients. Our data suggest that cereal fiber is a potentially protective component and may enhance overall longevity in MHD patients.