Kidney Week

Abstract: FR-PO0581

Serum Sodium Levels, Their Related Factors, and Association with All-Cause and Cardiovascular Mortality in Community-Dwelling Adults

Session Information

• Fluid, Electrolyte, and Acid-Base Disorders: Clinical - 2
  November 07, 2025 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Fluid, Electrolytes, and Acid-Base Disorders

• 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical

Authors

• Kabasawa, Keiko, Niigata University, Niigata, Japan

Keiko Kabasawa, MD, PhD, MPH

• Hosojima, Michihiro, Niigata University, Niigata, Japan

Michihiro Hosojima, MD, PhD

• Ito, Yumi, Niigata University, Niigata, Japan

Yumi Ito, MD, PhD

• Nakamura, Kazutoshi, Niigata University, Niigata, Japan

Kazutoshi Nakamura

• Tanaka, Junta, Niigata University, Niigata, Japan

Junta Tanaka, MD, PhD

• Yamamoto, Suguru, Niigata University, Niigata, Japan

Suguru Yamamoto, MD, PhD

Background

Abnormal serum sodium levels can result from a wide array of physical conditions and are well-known risk factors for death in hospitalized patients. However, little is known about such associations in community-dwelling adults.

Methods

A prospective cohort study conducted in Japan involved 7,178 community-dwelling adults (age 40–97 years; 50.1% women). We divided serum sodium levels at <140 (low), 140–142 (reference), and ≥143 (high) mmol/L. We explored factors related to serum sodium levels using multinomial logistic regression analysis and the association of serum sodium levels with all-cause and cardiovascular mortality, using Cox proportional hazards model.

Results

Median serum sodium level at baseline was 141 mmol/L. Factors related to a low serum sodium level were male sex, eGFR <60mL/min/1.73m², and diabetes. Factors related to a high serum sodium level were older age, drinking habit, and high body mass index. During a median follow-up of 8 years, 703 events occurred. Compared with the reference, a low serum sodium level was associated with a higher risk of all-cause and cardiovascular mortality (adjusted hazard ratio [95%CI] 1.48 [1.23, 1.78] and 1.77 [1.24, 2.54], respectively). When modeled with restricted cubic splines, the associations formed a U-shape, with a serum sodium level of 141 mmol/L having the lowest risk (Figure).

Conclusion

Demographic factors, kidney function, and diabetic status were correlated with serum sodium levels. The findings of this study indicate that even community-dwelling adults with low-normal serum sodium levels are at high risk of all-cause and cardiovascular mortality.

Figure. Association of serum sodium levels with all-cause and cardiovascular mortality

Funding

• Government Support – Non-U.S.

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.20251tkkh447