Table 1.

Baseline characteristics according to sex-specific tertiles of C-terminal FGF23

		Tertiles of C-terminal FGF23 (RU/mL)
Variables	Full cohort	Tertile I	Tertile II	Tertile III	Ptrend
		♂: <61.9	♂: 61.9–74.2	♂: >74.2
		♀: <58.4	♀: 58.4–82.9	♀: >82.9
Participants, n	5253	1744	1760	1749
Men, %	47	47	47	47
Age (years)	52 ± 12	51 ± 11	52 ± 11	53 ± 12	<0.001
BMI (kg/m2)	26.4 ± 4.2	25.9 ± 3.8	26.4 ± 4.2	27 ± 4.5	<0.001
Race (whites, %	96	94	96	96	0.013
Current smoker, %	27.6	20.6	26.6	35.4	<0.001
Systolic blood pressure (mmHg)	124 ± 17	123 ± 17	123 ± 17	124 ± 17	0.001
Diastolic blood pressure (mmHg)	72 ± 9	72 ± 9	72 ± 9	73 ± 8	0.21
Antihypertensive drugs, %	17.1	12.6	16.5	22.2	<0.001
Use of ACEIs/ARBs, %	6.5	4.8	7.1	7.7	<0.001
Current diabetes, %	3.9	2.6	3.4	5.8	<0.001
eGFRCKD-EPI (mL/min×1.73 m2)	95 ± 13	98 ± 13	95 ± 13	93 ± 14	<0.001
Plasma total cholesterol (mmol/L)a	5.4 ± 1.0	5.4 ± 1.0	5.4 ± 1.0	5.4 ± 1.0	0.37
Plasma hsCRP (mg/L), median (IQR)b	1.2 (0.6–2.8)	1.1 (0.5–2.4)	1.2 (0.6–2.7)	1.5 (0.7–3.4)	<0.001
Plasma sodium (mmol/L)c	140.7 ± 2.0	140.7 ± 2.1	140.7 ± 1.9	140.6 ± 2.1	0.03
Plasma potassium (mmol/L)d	4.2 ± 0.3	4.2 ± 0.3	4.2 ± 0.3	4.2 ± 0.3	0.12
Plasma phosphate (mmol/L)d	1.01 ± 0.27	0.99 ± 0.22	1.02 ± 0.28	1.03 ± 0.29	<0.001
Plasma calciumc	2.30 ± 0.11	2.29 ± 0.11	2.31 ± 0.11	2.30 ± 0.12	0.001
Plasma C-terminal FGF23 (RU/mL), median (IQR)	68.5 (56.1–85.1)	51.9 (46.7–56.1)	68.5 (64–73)	95.4 (85.1–116.7)	<0.001
Plasma PTH (pmol/L), median (IQR)e	4.8 (4.0–5.7)	4.7 (3.9–5.6)	4.8 (4.0–5.7)	4.9 (4.1–5.9)	0.009
Plasma 25(OH)D (ng/mL)f	59.7 ± 26.0	60.7 ± 27.0	61.2 ± 25.7	56.9 ± 25.2	<0.001
Haemoglobin (mmol/L)g	8.5 ± 0.7	8.5 ± 0.7	8.5 ± 0.7	8.5 ± 0.8	0.70
Plasma iron (μmol/L)h	15.9 ± 5.6	16.6 ± 5.3	16.3 ± 5.5	15.0 ± 6.0	<0.001
Plasma transferrin (g/L)h	2.6 ± 0.4	2.5 ± 0.4	2.5 ± 0.4	2.7 ± 0.4	<0.001
Plasma ferritin (μg/L), median (IQR)h	93 (45–169)	103 (55–180)	99 (50–175)	75 (29–148)	<0.001
Urine urea (g/24 h)f	21.7 ± 6.7	22.4 ± 6.9	21.8 ± 6.6	20.8 ± 6.5	<0.001
Urine creatinine (mg/24 h)i	1391 ± 376	1407 ± 381	1393 ± 374	1373 ± 372	0.008
Urine albumin (mg/24 h), median (IQR)	7.8 (5.8–11.5)	7.8 (5.9–11.3)	7.7 (5.8–12.3)	8.0 (5.8–12.3)	0.34

Data are presented as mean ± SD unless stated otherwise. ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blockade.

^aMissing in 23 cases.

^bMissing in 273 cases.

^cMissing in 112 cases.

^dMissing in 110 cases.

^eMissing in 99 cases.

^fMissing in 91 cases.

^gMissing in 13 cases.

^hMissing in 233 cases.

ⁱMissing in 71 cases.