Appendix Table 2.

Association of Calcium and Phosphorus With ln-FGF23, ucMGP, and Fetuin-A Levels^*

Variable	ln-FGF23		ucMGP		Fetuin-A
	Unadjusted β (95% CI)	P Value	Unadjusted β (95% CI)	P Value	Unadjusted β (95% CI)	P Value
ln-FGF23	–	–	−0.05 (−0.12 to 0.01)	0.116	0.10 (0.03 to 0.17)	0.004
ucMGP	−0.05 (−0.12 to 0.01)	0.116	–	–	0.27 (0.21 to 0.34)	<0.001
Fetuin-A	0.10 (0.03 to 0.17)	0.004	0.27 (0.21 to 0.34)	<0.001	–	–
Calcium†	0.11 (0.04 to 0.18)	0.001	0.06 (0.00 to 0.13)	0.064	0.08 (0.01 to 0.14)	0.027
Phosphorus	0.27 (0.21 to 0.34)	<0.001	0.10 (0.03 to 0.16)	0.006	0.09 (0.02 to 0.16)	0.008
	Adjusted β (95% CI)‡		Adjusted β (95% CI)‡		Adjusted β (95% CI)‡
ln-FGF23	–	–	−0.03 (−0.1 to 0.04)	0.39	0.06 (−0.01 to 0.13)	0.111
ucMGP	−0.03 (−0.09 to 0.04)	0.39	–	–	0.25 (0.19 to 0.32)	<0.001
Fetuin-A	0.05 (−0.01 to 0.12)	0.111	0.25 (0.18 to 0.31)	<0.001	–	–
Calcium†	0.09 (0.02 to 0.15)	0.008	0.04 (−0.03 to 0.11)	0.22	0.05 (−0.02 to 0.12)	0.147
Phosphorus	0.19 (0.12 to 0.25)	<0.001	0.08 (0.01 to 0.15)	0.025	0.02 (−0.05 to 0.09)	0.62

ln-FGF23 = natural log–transformed fibroblast growth factor 23; ucMGP = uncarboxylated matrix Gla protein.

^*Data are coefficients of regression (β) with 95% CIs representing SD change in ln-FGF23, ucMGP, and fetuin-A levels per SD change in predictor variables (FGF23 was log-transformed for regression analysis because of nonparametric distribution).

^†Adjusted calcium = total calcium + (4.0 − serum albumin) × 0.8.

^‡Adjusted for age, sex, race, and estimated glomerular filtration rate.