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Abstract: TH-PO128

The Association Between Fibroblast Growth Factor 23 and Blood Pressure in a Hemodialysis Cohort

Session Information

Category: Bone and Mineral Metabolism

  • 502 Bone and Mineral Metabolism: Clinical

Authors

  • Mbah, Mireille M., The University of Texas Southwestern Medical Center, Dallas, Texas, United States
  • Gattineni, Jyothsna, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
  • Van Buren, Peter N., The University of Texas Southwestern Medical Center, Dallas, Texas, United States
Background

Mineral bone disease (MBD) is associated with mortality in hemodialysis (HD) patients, and we recently found associations between hyperphosphatemia and vasoconstriction/endothelial cell dysfunction in a small HD cohort. We hypothesized that fibroblast growth factor 23 (FGF23), the earliest MBD marker, would be independently associated with blood pressure in this cohort.

Methods

In a cohort of hypertensive HD patients, we measured plasma FGF23 from remaining frozen samples using ELISA. We conducted correlation and linear regression analysis to determine the association between FGF23 and peridialytic BP metrics and other lab parameters.

Results

There were 34 participants (53% women, 59% Black, 45% with diabetes) with a mean age of 46.8 years, mean pre-HD systolic BP of 160 (19) mmHg, mean serum phosphate of 6.5 (2.3) mg/dL and median FGF23 of 3264 (1042-6817) ng/mL. LogFGF23 did not differ based on diabetes status or sex, but it was higher in Black vs. White participants (p=.003). FGF23 correlated with phosphate (r=0.5, p=.001), but not PTH. Table 1 shows that logFGF23 was associated with almost all peridialytic BP metrics in univariate analysis that remained independent after controlling for phosphate, but were no longer significant after controlling for race.

Conclusion

FGF23 was associated with phosphate in hypertensive HD patients, and it was higher in Black vs. White participants. Associations between FGF23 and BP were independent of phosphate, but race was a confounding variable in this small cohort. Further larger studies are required better understand mechanisms by which FGF23 and MBD in general impact BP and CV health as well as to determine the generalizability of the race-based differences found in this study.

Linear Regression Analysis Using LogFGF23 as the Outcome Variable
 Univariate Regression Coefficient (p-value)Multivariate regression coefficient (p-value) controlling for phosphateMultivariate regression coefficient (p-value) controlling for phosphate and race
Seated Pre-HD SBP12.9 (0.01)14 (0.02)6 (0.3)
Seated Post-HD SBP6.98 (0.2)--
Seated Pre-HD MAP11 (0.01)10.7 (0.05)4.98 (0.3)
Seated Post-HD MAP10.3 (0.005)9.6 (0.02)9.1 (0.03)
Standing Pre-HD SBP12.1 (0.03)16.5 (0.01)3.76 (0.6)
Standing Post-HD SBP14.7 (0.3)15.0 (0.04)8.1 (0.3)
Standing Pre-HD MAP11.7 (0.009)11.8 (0.02)4.2 (0.4)
Standing Post-HD MAP12.1 (0.01)11.2 (0.04)8.1 (0.2)

HD=Hemodialysis, SBP=Systolic Blood Pressure, MAP=Mean Arterial Pressure

Funding

  • NIDDK Support