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

Objective: To determine the association between dietary fiber intake (DFI) and all-cause mortality and cardiovascular mortality in Chinese maintenance hemodialysis (MHD) patients, considering fiber type and source.

Methods: 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 non-linear relationship between the total cereal fiber and mortality. Subgroup and sensitivity analysis was performed to examine the robustness.

Results: 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 p_non-linear > 0.05).

Conclusions: 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.