The prevalence of predialysis hyperkalemia and associated characteristics among hemodialysis patients: The RE-UTILIZE study.

Introduction: Hyperkalemia (HK), defined as serum potassium (K ) >5.0 mEq/L, is an independent predictor of mortality in patients on maintenance hemodialysis (HD). This study investigated the annual prevalence of HK and examined patient characteristics potentially associated with a higher annual HK prevalence.

Methods: This retrospective observational cohort study used Dialysis Outcomes and Practice Patterns Study (DOPPS) survey data from US patients undergoing in-center HD thrice weekly from 2018 to 2019. The primary endpoint was the proportion of patients with any predialysis HK (K  >5.0 mEq/L) within 1 year from the index date (date of DOPPS enrollment), using the first hyperkalemic K value. Secondary endpoints were the proportion of patients with moderate-to-severe (K  >5.5 mEq/L) or severe (K  >6.0 mEq/L) HK.

Findings: Overall, 9347 patients on HD were included in this analysis (58% male and 49% aged >66 years). Any predialysis HK (K  >5.0 mEq/L) occurred in 74% of patients within 1 year of the index date, 52% within 3 months, and 38% within 1 month. The annual prevalence of moderate-to-severe and severe HK was 43% and 17%, respectively. Recurrent HK (at least two K  >5.0 mEq/L within 1 year) occurred in 60% of patients, and 2.8% of patients were prescribed an oral K binder. Multivariable logistic regression analysis showed younger age, female sex, Hispanic ethnicity, and renin-angiotensin-aldosterone system inhibitor use were significantly associated with a higher annual prevalence of any predialysis HK, while Black race, obesity, recent initiation of HD, and dialysate K bath concentration ≥3 mEq/L were associated with a lower prevalence of HK.

Discussion: The annual prevalence of predialysis HK and recurrence were high among US patients on HD, whereas oral K binder use was low. Further studies are needed to understand the impact of dialysate K bath concentrations on predialysis HK among patients on HD.