Table 3.

Univariate and multivariate linear regression analyses between inflammatory markers as dependent variables and fibroblast growth factor 23 as primary exposure

UnadjustedAdjusted Model AaAdjusted Model Bb
Difference (95% CI)P ValueDifference (95% CI)P ValueDifference (95% CI)P Value
LnIL-6
 LnFGF230.40 (0.36–0.43)<0.0010.29 (0.25–0.33)<0.0010.29 (0.25–0.33)<0.001
 FGF23 quartile 1Reference
 FGF23 quartile 20.24 (0.16–0.310<0.0010.14 (0.06–0.21)<0.0010.13 (0.05–0.21)<0.001
 FGF23 quartile 30.42 (0.35–0.50)<0.0010.25 (0.17–0.34)<0.0010.23 (0.15–0.32)<0.001
 FGF23 quartile 40.83 (0.75–0.90)<0.0010.57 (0.48–0.65)<0.0010.55 (0.46–0.64)<0.001
LnCRP
 LnFGF230.28 (0.23–0.33)<0.0010.19 (0.14–0.25)<0.0010.22 (0.16–0.27)<0.001
 FGF23 quartile 1Reference
 FGF23 quartile 20.05 (−0.06 to 0.17)0.340.001 (−0.11 to 0.11)0.990.02 (−0.09 to 0.13)0.80
 FGF23 quartile 30.24 (0.13–0.35)<0.0010.17 (0.05–0.29)0.0040.19 (0.07–0.30)0.002
 FGF23 quartile 40.59 (048–0.70)<0.0010.37 (0.24–0.50)<0.0010.40 (0.27–0.53)<0.001
LnTNF-α
 LnFGF230.28 (0.25–0.30)<0.0010.14 (0.10–0.17)<0.0010.14 (0.10–0.17)<0.001
 FGF23 quartile 1Reference
 FGF23 quartile 20.22 (0.16–0.28)<0.0010.10 (0.03–0.16)0.0020.09 (0.03–0.15)0.003
 FGF23 quartile 30.40 (0.34–0.46)<0.0010.17 (0.11–0.23)<0.0010.17 (0.11–0.24)<0.001
 FGF23 quartile 40.59 (0.53–0.65)<0.0010.28 (0.21–0.35)<0.0010.28 (0.20–0.35)<0.001
Fibrinogen
 LnFGF230.44 (0.07–0.28)<0.0010.13 (0.07–0.18)<0.0010.09 (0.03–0.14)0.001
 FGF23 quartile 1Reference
 FGF23 quartile 20.18 (0.07–0.28)<0.001−0.05 (−0.15 to 0.05)0.40−0.07 (−0.17 to 0.03)0.20
 FGF23 quartile 30.56 (0.46–0.66)<0.0010.12 (0.02–0.23)0.020.09 (0.02–0.20)0.10
 FGF23 quartile 40.98 (0.88–1.08)<0.0010.33 (0.22–0.45)<0.0010.25 (0.13–0.37)<0.001
  • CI, confidence interval; Ln, log-normal; FGF23, fibroblast growth factor 23; P for trend < 0.0001 for all comparisons.

  • a Model A: Adjusted for age, sex, black race, Hispanic ethnicity, diabetes, current smoking, body mass index, use of statins, estimated GFR, and urinary albumin-to-creatinine ratio.

  • b Model B: Adjusted for model A plus phosphate and parathyroid hormone.