Hyperkalemia development in non-dialysis chronic kidney disease (ND-CKD) patients predicts progression to end-stage renal disease (ESRD), according to researchers.
In a pooled cohort of 2443 CKD patients (mean age 65 years) referred to 46 nephrology clinics in Italy, hyperkalemia was common, Luca De Nicola, MD, PhD, of the University of Campania “Luigi Vanvitelli,” and colleagues reported in the Journal of Clinical Medicine. The team defined 4 groups based on patients’ hyperkalemia status at visit 1 (baseline) and visit 2 (12 months): absent (no-no), resolving (yes-no), new onset (no-yes), and persistent (yes-yes).
Hyperkalemia was absent in 46%, resolving in 17%, new onset in 15%, and persistent in 22% of patients. The vast majority with hyperkalemia had mild (5.0–5.4 mEq/L) to moderate (5.5–5.9 mEq/L) serum potassium levels, with just 4% reaching severe status (6 mEq/L or higher).
Over 3.6 years of follow up, 567 patients progressed to ESRD and 349 died. According to multivariate competing risk analyses, those with new onset or persistent hyperkalemia had 34% and 27% higher risks for ESRD, respectively, than those without hyperkalemia. Declines in estimated glomerular filtration rate did not account for the excess risk.
Renin-angiotensin-system inhibitors (RASi) were prescribed to 79% of patients. When new-onset or persistent hyperkalemia was coupled with discontinuation of RASi, the risk for ESRD increased by 57%.
The team found no greater risks for mortality among those with hyperkalemia. The authors offered potential explanations for this finding. In their patients, they noted, ESRD “overcomes mortality, as expected in the tertiary nephrology care setting.” They also observed that nephrologists start dialysis in the presence of hyperkalemia that is refractory to therapy to prevent deaths related to potential additional increases in serum potassium.
Gaining insights into the prevalence and prognostic role of hyperkalemia in the setting of tertiary nephrology care is important, the investigators stated, because nephrology clinics are the appropriate reference of care for ND-CKD patients.
“In this setting, improving risk stratification is mandatory to optimize practice of nephrology workforce, which is limited today and projected to further shrink in the next future,” they wrote.
Hyperkalemia contributors, such as medications and supplements, could not be assessed, which is a study limitation.
Provenzano M, Minutolo R, Chiodini P, et al. J. Competing-risk analysis of death and end stage kidney disease by hyperkalaemia status in non-dialysis chronic kidney disease patients receiving stable nephrology care. J Clin Med. 2018;7:499. DOI:10.3390/jcm7120499