Dynamic potassium variability (K-CV) as an independent predictor of mortality in maintenance hemodialysis

Serum potassium fluctuations are common but understudied in maintenance hemodialysis (MHD) patients. This retrospective cohort study investigated the association between serum potassium variability, measured by the coefficient of variation (K-CV), and all-cause mortality in 201 MHD patients. Patients were divided into low and high K-CV groups according to the median K-CV cutoff and followed for a median of 72 months. Multivariate Cox regression, adjusted for confounders, revealed that patients in the high K-CV group had a significantly increased mortality risk compared to the low K-CV group (adjusted HR = 1.537, 95% CI: 1.026-2.302, p = 0.037). When analyzed continuously, log(K-CV) showed a strong dose-response relationship with mortality (HR = 7.627, p = 0.010). Subgroup analyses indicated this association was particularly pronounced in patients with lower inflammation and better nutritional status. These findings demonstrate that K-CV, a marker of serum potassium variability, serves as an independent predictor of all-cause mortality in MHD patients. Its prognostic value supports the use of K-CV for risk stratification to identify high-risk patients requiring intensive monitoring and tailored potassium management strategies in dialysis care.