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Abstract: FR-PO1099

High Fibroblast Growth Factor 23 Levels Increase Risk of SARS-CoV-2 Infection and Mortality in End-Stage CKD on Hemodialysis: A Three-Year Follow-Up Prospective Cohort

Session Information

  • COVID-19 - II
    November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Coronavirus (COVID-19)

  • 000 Coronavirus (COVID-19)


  • Toro, Luis, Hospital Clinico Universidad de Chile, Santiago, Chile
  • Michea, Luis, Hospital Clinico Universidad de Chile, Santiago, Chile
  • Sanhueza, Maria Eugenia, Hospital Clinico Universidad de Chile, Santiago, Chile
  • Torres, Ruben, Hospital Clinico Universidad de Chile, Santiago, Chile
  • Elgueta, Leticia, Hospital Clinico Universidad de Chile, Santiago, Chile
  • Alvo, Miriam, Hospital Clinico Universidad de Chile, Santiago, Chile

End-stage renal disease (ESRD) patients are a population with high rates of COVID-19 and mortality. Fibroblast Growth Factor 23 (FGF23) is a protein hormone associated with impaired immune response in experimental murine models. ESRD patients have high plasma levels of FGF23, and recent studies suggest that patients with high FGF23 levels have increased rates of severe infections and infection-related mortality. Therefore, our objective was to evaluate the association between FGF23 levels and the development of SARS-CoV-2 infection in ESRD patients on hemodialysis.


A prospective cohort of ESRD patients on hemodialysis who had plasma intact FGF23 (iFGF23) measurements in 2019. We evaluated rates of SARS-CoV-2 infection and severe COVID-19 (COVID-related hospitalization or death) between January 2020 and December 2022 (3-year follow-up). In addition, we evaluated potential predictors of outcomes using multivariate analyses.


243 patients were evaluated. Age: 60.4±10.8 years. Women: 120 (49.3%), diabetes: 110 (45.2%). 57 patients developed COVID-19 (23.4%), 41 were hospitalized, and 46 died (mortality rate: 18.9%). Patients with high iFGF23 (equal to or greater than 350 pg/mL) had a higher rate of SARS-CoV-2 infection (30.8% vs. 18.1%; Hazard ratio: 1.81 [1.08–3.04], p=0.024) and severe COVID-19 (23.1% vs. 11.9%; Hazard ratio: 2.02 [1.09–3.73], p=0.031) compared to those with lower levels (Figures 1 and 2). Multivariate analysis showed that elevated iFGF23 plasma levels were an independent risk factor for SARS-CoV-2 infection and severe COVID-19.


Our data suggest that increased iFGF23 levels are a risk factor for developing COVID-19 in ESRD patients on hemodialysis. In addition, these data support the potential immunosuppressive effect of FGF23, which may contribute to the increased risk of adverse clinical outcomes in renal patients.
Study supported by FONDECYT Regular 1221571.


  • Government Support – Non-U.S.