Lower serum potassium associated with increased mortality in dialysis patients: A nationwide prospective observational cohort study in Korea

Sunhwa Lee, Eunjeong Kang, Kyung Don Yoo, Yunhee Choi, Dong Ki Kim, Kwon Wook Joo, Seung Hee Yang, Yong Lim Kim, Shin Wook Kang, Chul Woo Yang, Nam Ho Kim, Yon Su Kim, Hajeong Lee

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28 Citations (Scopus)


Background Abnormal serum potassium concentration has been suggested as a risk factor for mortality in patients undergoing dialysis patients. We investigated the impact of serum potassium levels on survival according to dialysis modality. Methods A nationwide, prospective, observational cohort study for end stage renal disease patients has been ongoing in Korea since August 2008. Our analysis included patients whose records contained data regarding serum potassium levels. The relationship between serum potassium and mortality was analyzed using competing risk regression. Results A total of 3,230 patients undergoing hemodialysis (HD, 64.3%) or peritoneal dialysis (PD, 35.7%) were included. The serum potassium level was significantly lower (P < 0.001) in PD (median, 4.5 mmol/L; interquartile range, 4.0-4.9 mmol/L) than in HD patients (median, 4.9 mmol/L; interquartile range, 4.5-5.4 mmol/L). During 4.4 ± 1.7 years of follow-up, 751 patients (23.3%) died, mainly from cardiovascular events (n = 179) and infection (n = 120). In overall, lower serum potassium level less than 4.5 mmol/L was an independent risk factor for mortality after adjusting for age, comorbidities, and nutritional status (sub-distribution hazard ratio, 1.30; 95% confidence interval 1.10-1.53; P = 0.002). HD patients showed a U-shaped survival pattern, suggesting that both lower and higher potassium levels were deleterious, although insignificant. However, in PD patients, only lower serum potassium level (<4.5 mmol/L) was an independent predictor of mortality (sub-distribution hazard ratio, 1.35; 95% confidence interval 1.00-1.80; P = 0.048). Conclusion Lower serum potassium levels (<4.5 mmol/L) occur more commonly in PD than in HD patients. It represents an independent predictor of survival in overall dialysis, especially in PD patients. Therefore, management of dialysis patients should focus especially on reducing the risk of hypokalemia, not only that of hyperkalemia.

Original languageEnglish
Article numbere0171842
JournalPloS one
Issue number3
Publication statusPublished - 2017 Mar

Bibliographical note

Publisher Copyright:
© 2017 Lee et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

All Science Journal Classification (ASJC) codes

  • General


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