Kidney Week

Abstract: PO0480

Serum Potassium and Survival Among Advanced CKD Patients Transitioning to Dialysis

Session Information

• CKD Risk Factors: Diet, Environment, Lifestyle
  October 22, 2020 | Location: On-Demand
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Narasaki, Yoko, University of California Irvine, Irvine, California, United States

Yoko Narasaki,

• Kalantar-Zadeh, Kamyar, University of California Irvine, Irvine, California, United States

Kamyar Kalantar-Zadeh,

• Ferrey, Antoney Joseph, University of California Irvine, Irvine, California, United States

Antoney Joseph Ferrey,

• Tantisattamo, Ekamol, University of California Irvine, Irvine, California, United States

Ekamol Tantisattamo,

• You, Amy Seung, University of California Irvine, Irvine, California, United States

Amy Seung You,

• Streja, Elani, University of California Irvine, Irvine, California, United States

Elani Streja,

• Ivaturi, Kaushik, University of California Irvine, Irvine, California, United States

Kaushik Ivaturi,

• Wenziger, Cachet, University of California Irvine, Irvine, California, United States

Cachet Wenziger,

• Hsiung, Jui-Ting, University of California Irvine, Irvine, California, United States

Jui-Ting Hsiung,

• Nguyen, Danh V., University of California Irvine, Irvine, California, United States

Danh V. Nguyen,

• Kovesdy, Csaba P., The University of Tennessee Health Science Center, Memphis, Tennessee, United States

Csaba P. Kovesdy,

• Rhee, Connie, University of California Irvine, Irvine, California, United States

Connie Rhee,

Background

Most laboratories designate a wide reference range for "normal" serum potassium levels (3.5-<5.5 mEq/L), yet the precise concentrations associated with favorable outcomes in chronic kidney disease (CKD) remain uncertain. While dietary potassium is commonly restricted in CKD patients to mitigate hyperkalemia, there may be ill effects of this strategy by restricting healthy potassium-rich foods (fruits, vegetables). We hypothesized that high-normal serum potassium levels are associated with better long-term survival in advanced non-dialysis dependent (NDD) CKD patients transitioning to dialysis.

Methods

Among 43,798 US Veterans with NDD-CKD transitioning to end-stage renal disease (ESRD) over 10/2007-3/2015, we examined the association of serum potassium levels averaged over the one-year pre-dialysis transition period (pre-ESRD prelude period) with post-ESRD mortality (Fig 1A) using national Veterans Affairs (VA) data linked to United States Renal Disease System data. Associations of serum potassium levels (categorized as <3.5, 3.5-<4.0, 4.0-<4.5, 4.5-<5.0, and 5.0-<5.5mEq/L) with all-cause mortality were estimated using adjusted Cox models.

Results

In adjusted Cox analyses, high-normal serum potassium levels ranging from 5.0-<5.5mEq/L were associated with greater survival (ref: 4.5-<5.0mEq/L): HR (95%CI): 0.95 (0.91-0.98) (Fig 1B). In contrast, serum potassium concentrations at or below low-normal serum potassium ranges were associated with higher death risk (ref: 4.5-<5.0mEq/L): HRs (95%CIs) 1.07 (1.04, 1.10), 1.05 (1.01, 1.09), and 1.16 (1.06, 1.27) for serum potassium levels 4.0-<4.5, 3.5-<4.0, and <3.5mEq/L, respectively.

Conclusion

In NDD-CKD patients transitioning to dialysis, serum potassium levels in the high-normal range were associated with greater long-term survival, whereas serum potassium levels at or below low-normal ranges were associated with higher long-term death risk. Further studies are needed to determine whether dietary factors may be a potential mechanistic link underlying these relationships.

Funding

• NIDDK Support