Hyperkalemia in Kidney Transplant Recipients

Patients with kidney disease and hyperkalemia are at risk for adverse outcomes. There are few data available regarding outcomes of hyperkalemia in kidney transplant recipients. Elisabetta Bussalino and colleagues at the University of Genoa, Italy, conducted a study to examine the prevalence and clinical correlates of hyperkalemia in stable kidney transplant recipients receiving standard-of-care immunosuppressive therapy.

Results of the study were reported online in Internal and Emergency Medicine [10.1007/s11739-021-02649-4].

The study included 160 stable kidney transplant recipients (post-transplant vintage 46.6 months). Most of the cohort (96.2%) were receiving calcineurin inhibitor-based immunosuppressive therapy. Hyperkalemia was defined as plasma potassium level >5 mEq/L, confirmed in two consecutive samples. Office blood pressure was measured, and renal graft function was expressed by estimated glomerular filtration rate (eGFR), calculated using the Chronic Kidney Disease-Epidemiology Collaboration formula.

The prevalence of hyperkalemia was 8.8%; plasma potassium >5.5 mEq/L was found in 2.5% of the 160 stable kidney transplant recipients. Results of univariate logistic regression demonstrated significant associations between hyperkalemia and serum urea concentration (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.05 for each 1 mg/dL increase), total carbon dioxide (OR, 0.77; 95% CI, 0.66-0.90 for each 1 mmol/L increase), presence of arterial hypertension (OR, 4.01; 95% CI, 1.3-12.64), use of renin-angiotensin-aldosterone system (RAAS) inhibitors (OR, 5.26; 95% CI, 1.6-17.7), and eGFR <30 mL/min/1.73 m² (OR, 7.51; 95% CI, 2.37-23.77).

In multivariable backward stepwise regression analysis, there were significant associations between hyperkalemia and the presence of metabolic acidosis (OR, 0.83; 95% CI, 0.69-0.99; P=.04), arterial hypertension (OR, 4.65; 95% CI, 1.01-17.46; P=.03), and use of RAAS inhibitors (OR, 6.11; 95% CI 1.03-25.96); P=.03).

“We conclude that in stable kidney transplant recipients the prevalence of hyperkalemia is about 9%, slightly lower than previously reported. Moreover, it is not associated with eGFR, but with metabolic acidosis, arterial hypertension, and the use of RAAS inhibitors,” the researchers said.