Kidney Week

Abstract: TH-PO1125

Association of Serum Sodium Concentration and Mortality in Patients with CKD

Session Information

• CKD: Therapies, Innovations, and Insights
  November 06, 2025 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2302 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

• Shah, Syed Muhammad Obaida M, The University of Tennessee Health Science Center College of Medicine, Memphis, Tennessee, United States

Syed Muhammad Obaida M Shah, MD

• Ramrattan, Amit, The University of Tennessee Health Science Center College of Medicine, Memphis, Tennessee, United States

Amit Ramrattan, MD, MBBS

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

Csaba P. Kovesdy, MD, FASN

• Wall, Barry M., The University of Tennessee Health Science Center College of Medicine, Memphis, Tennessee, United States

Barry M. Wall, MD

• Hussein, Wael F., The University of Tennessee Health Science Center College of Medicine, Memphis, Tennessee, United States

Wael F. Hussein, MBBS, MSc, FASN

Background

Dysnatremia is associated with poor outcomes, but the degree to which these associations reflect underlying disease severity is not clear. We examined the association between serum sodium concentration (SNa) and mortality in patients with non-dialysis dependent chronic kidney disease (CKD), to test whether SNa is an independent factor in relation to mortality or a marker of underlying risk.

Methods

We examined a historic cohort of 631 outpatients with eGFR <60 ml/min/1.73m² from a single institution followed over a median of 6.4 years. SNa was examined both as a continuous and a categorical (≤135, 136–145, and ≥146 mmol/L) variable. We examined the association between SNa and all-cause mortality in Cox regression models, with adjustment for patient demographics, comorbidities, blood pressure, eGFR, proteinuria, and medications.

Results

The mean±SD age was 67.5 ± 10.6 years and 96.8% were male. Diabetes, heart failure, and liver disease were present in 58%, 21%, and 10% respectively. Hypo- and hypernatremia were present in 6.5% and 4.1% of patients respectively. Mortality rates were 129/1,000 patient years (PY) (<=135 mmol/L), 97/1,000 PY (136–145 mmol/L), and 113/1,000 PY (≥146 mmol/L). There was a U-shaped association between SNa and mortality in the unadjusted analysis. However, in fully adjusted models, these associations were no longer statistically significant (HR for ≤135 vs 136–145: 1.02 [95% CI: 0.65–1.61], p=0.93; HR for ≥146: 0.96 [0.58–1.59], p=0.87).

Conclusion

Baseline SNa had a significant unadjusted U-shaped association with mortality, but this association was fully attenuated after accounting for other factors including comorbidities, proteinuria, and eGFR. These findings suggest that the SNa–mortality relationship is largely confounded by underlying illness severity.

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.20259113bdre