Electrolyte trajectories in chronic kidney disease primary Care: An 11-year follow-up study.

Background and aims: Long-term disturbances in mineral metabolism and their effects on chronic kidney disease (CKD) outcomes remain unclear. This study aimed to investigate whether longitudinal trajectories of sodium (Na), potassium (K), calcium (Ca), and phosphorus (P) are associated with the risk of progressing to dialysis.

Methods: We conducted a longitudinal cohort study including 2978 pre-dialysis CKD patients aged ≥18 years. Patients were stratified into four groups using group-based multi-trajectory modeling based on changes in serum Na, K, Ca, and P. The association between these trajectory groups and incident dialysis was assessed using Cox proportional hazards regression models, adjusted for baseline estimated glomerular filtration rate (eGFR) and other potential confounders.

Results: The mean age of the cohort was 70.02 years, with a median follow-up duration of 2.86 years. Patients in Group 3-characterized by higher K and P and lower Na and Ca-had a 3.68-fold higher risk of initiating dialysis compared to Group 1, with an average annual eGFR decline of -2.6 mL/min/1.73 m² (p < 0.0001). In sensitivity analyses limited to patients with CKD stage 3b, similar associations were observed. Furthermore, multi-electrolyte trajectories in the first 3 years were predictive of dialysis risk over the subsequent 2 years (hazard ratio = 3.41; 95 % CI: 1.02-11.40) in Group 3 versus Group 1.

Conclusions: Longitudinal changes in serum Na, K, Ca, and P levels-especially within the first three years-are associated with increased risk of dialysis in CKD patients. Early identification of adverse electrolyte patterns may inform timely interventions to delay disease progression.