Abstract: FR-PO393

Fibroblast Growth Factor 23 and Kidney Function Decline: The Health Aging and Body Composition Study

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 301 CKD: Risk Factors for Incidence and Progression

Authors

  • Drew, David A., Tufts Medical Center, Boston, Massachusetts, United States
  • Katz, Ronit, University of Washington, Seattle, Washington, United States
  • Kritchevsky, Stephen, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States
  • Ix, Joachim H., UCSD, San Diego, California, United States
  • Shlipak, Michael, San Francisco VA Medical Center, San Francisco, California, United States
  • Newman, Anne B., University of Pittsburgh, Pittsburgh, Pennsylvania, United States
  • Fried, Linda F., VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, United States
  • Sarnak, Mark J., Tufts Medical Center, Boston, Massachusetts, United States
  • Gutierrez, Orlando M., UAB School of Medicine , Birmingham, Alabama, United States
Background

Fibroblast growth factor 23 (FGF-23) is a potential biomarker for kidney disease. Previous studies have shown FGF-23 to be a risk factor for incident end-stage renal disease (ESRD); however, there are less data on the association of FGF-23 with earlier kidney related outcomes.

Methods

Serum FGF-23 was assayed using an intact ELISA assay in 2,496 participants of the Healthy Aging and Body Composition Study, a cohort of well-functioning older adults. Kidney function was estimated by assaying cystatin C at baseline and years 3 and 10. The associations between FGF-23 and decline in kidney function (defined by estimated glomerular filtration rate (eGFR) decline ≥30% or ≥3 ml/min/year) and incident CKD (incident eGFR <60 ml/min/1.73 m2 and ≥1 ml/min/year decline) were evaluated. Models were adjusted for demographics, baseline eGFR, urine albumin/creatinine ratio, comorbidity, and serum calcium, phosphorus and parathyroid hormone.

Results

The mean (SD) age was 75 (3) years, with 52% female, and 38% black. There were 405 persons with 30% decline, 702 with > 3 ml/min/year decline, and 536 with incident CKD. In fully adjusted continuous models, FGF-23 concentrations were not associated with kidney function decline (OR [95%CI] = 0.99 [0.82, 1.19] for ≥30% decline and OR= 1.16 [0.99, 1.36] for ≥3 ml/min/year decline), or incident CKD (IRR= 1.05 [0.91, 1.22] per two fold higher FGF-23 level). In quartile analysis, the highest quartile of FGF-23 was significantly associated with incident CKD (IRR= 1.26 [1.02, 1.57] for highest vs lowest quartile).

Conclusion

Higher FGF-23 concentrations were not consistently associated with decline in kidney function or incident CKD in community-dwelling older adults.

Funding

  • NIDDK Support