Dietary potassium intake from different food sources and mortality in maintenance haemodialysis patients: a multicentre prospective cohort study

The association between dietary potassium intake and mortality in maintenance haemodialysis (MHD) patients remains controversial, particularly regarding potassium from different dietary sources. In this multicentre prospective cohort study, dietary potassium intake was assessed using 24-hour dietary recalls. Cox proportional hazards models were used to evaluate associations with all-cause and cardiovascular mortality. Restricted cubic splines assessed dose-response relationships, and sensitivity analyses included adjustment for dietary quality indicators, exclusion of serum potassium, exclusion of deaths within the first year, and competing-risk models. The lowest tertile of total dietary potassium intake was associated with higher all-cause mortality (adjusted hazard ratio [aHR]: 1·36, 95 % CI: 1·02-1·81). The lowest tertile of plant-based potassium intake was associated with increased all-cause mortality (aHR: 1·54, 95% CI: 1·19-1·99) and cardiovascular mortality (aHR: 1·50, 95% CI: 1·05-2·14). Restricted cubic spline analyses demonstrated inverse dose-response relationships between total dietary potassium intake and both mortality outcomes and between plant-based potassium intake and all-cause mortality. Dietary potassium intake was not associated with serum potassium levels or hyperkalaemia risk, whereas severe hyperkalaemia (serum potassium ≥6·0 mmol/L) independently predicted cardiovascular mortality (aHR: 1·59, 95% CI: 1·06-2·38). Lower dietary potassium intake, particularly from plant sources, was associated with increased mortality risk among MHD patients. These findings support a more individualised approach to dietary potassium management in MHD patients.