ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: PO1140

Association of Serum Sodium Levels with Bone Mineral Density, Fracture, and Mortality in Patients Undergoing Maintenance Hemodialysis

Session Information

Category: Fluid, Electrolyte, and Acid-Base Disorders

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

Authors

  • Soeda, Keisuke, Tokai Daigaku, Hiratsuka, Kanagawa, Japan
  • Komaba, Hirotaka, Tokai Daigaku, Hiratsuka, Kanagawa, Japan
  • Nakagawa, Yosuke, Tokai Daigaku, Hiratsuka, Kanagawa, Japan
  • Wada, Takehiko, Tokai Daigaku, Hiratsuka, Kanagawa, Japan
  • Kakuta, Takatoshi, Tokai Daigaku Igakubu Fuzoku Hachioji Byoin, Hachioji, Tokyo, Japan
  • Fukagawa, Masafumi, Tokai Daigaku, Hiratsuka, Kanagawa, Japan
Background

Hyponatremia is implicated in pathological bone resorption and has been identified as a risk factor for bone fracture in the general population, but limited data exist in patients undergoing dialysis.

Methods

We analyzed a historical cohort of 2,292 patients undergoing maintenance hemodialysis in Japan. We first examined the association of baseline serum sodium levels with metacarpal bone mineral density (BMD) in a subcohort of 456 patients with available data. Next, we examined the association of baseline serum sodium levels with incident fracture and mortality in the overall cohort, using Cox regression models adjusted for potential confounders (age, sex, dialysis vintage, diabetes, prior cardiovascular disease, history of fracture, body mass index, hemoglobin, albumin, and creatinine) and competing risks regression models accounting for death as a competing endpoint.

Results

Baseline mean ± SD serum sodium level in the overall cohort was 139.7 ± 2.9 mEq/L, and among patients with available data, median metacarpal BMD T-score was -2.05 (IQR, -3.35 to -0.99). Serum sodium levels were not associated with metacarpal BMD T-score in unadjusted or adjusted models. During a median follow-up of 5.4 years (IQR, 2.5-7.0 years), 712 patients died; 113 experienced clinical fractures; and 64 experienced asymptomatic vertebral fractures as estimated by height loss. In adjusted Cox regression models, serum sodium levels were associated with mortality (HR, 0.95 per 1 mEq/L higher; 95% CI, 0.92-0.98) but not incident clinical fracture (HR, 0.97 per 1 mEq/L higher; 95% CI, 0.90-1.04) or any fracture (a composite of clinical fracture and vertebral fracture). Similar results were obtained in competing risks regression models.

Conclusion

Serum sodium levels were associated with mortality but not BMD or incident fracture in maintenance hemodialysis patients.