Table 5.

Associations of baseline fibroblast growth factor 23 concentrations with risk of 50% decline from baseline eGFR, ESRD, or the composite end point in the HALT-PKD Study B

50% Loss of eGFRESRDComposite End Pointa
No. of EventsHR (95% CI)No. of EventsHR (95% CI)No. of EventsHR (95% CI)
UnadjustedAdjustedbUnadjustedAdjustedbUnadjustedAdjustedb
Per FGF23 doubling1752.35 (1.87 to 2.97)1.65 (1.26 to 2.18)1083.35 (2.51 to 4.47)1.41 (1.00 to 1.98)2232.68 (2.18 to 3.30)1.72 (1.35 to 2.20)
FGF23 quartiles
 1221.001.00101.001.00241.001.00
 2502.92 (1.76 to 4.85)2.78 (1.62 to 4.79)162.06 (0.93 to 4.57)1.24 (0.51 to 3.02)552.84 (1.75 to 4.60)2.50 (1.50 to 4.19)
 3503.77 (2.27 to 6.26)2.91 (1.67 to 5.08)375.66 (2.80 to 11.47)2.72 (1.22 to 6.07)674.43 (2.76 to 7.09)3.02 (1.81 to 5.04)
 4535.66 (3.41 to 9.40)2.91 (1.64 to 5.19)459.03 (4.49 to 18.14)2.04 (0.90 to 4.65)776.92 (4.34 to 11.03)3.11 (1.84 to 5.25)
  • HR, hazard ratio; 95% CI, 95% confidence interval; FGF23, fibroblast growth factor 23.

  • a Composite of 50% reduction in eGFR, ESRD, or death.

  • b Adjusted by age, sex, body mass index, systolic BP, randomization group, calcium, phosphorus, eGFR, urinary albumin excretion, and polycystic kidney disease genotype.