Table 3.

Blood and urine markers of mineral metabolism by categories of creatinine clearance. Results are depicted as means ± standard deviation or median (interquartile range).

	Crcl > 60	Crcl 45–60	Crcl 30–44	Crcl < 30	P (trend)
N	20	21	22	11
Serum phosphorus (mg/dl)	2.7 ± 0.4	3.1 ± 0.6	3.3 ± 0.6	3.0 ± 0.6	0.12
Urinary phosphate excretion (mg/d)	993 ± 324	627 ± 141	654 ± 211	377 ± 139	<0.001
Serum calcium (mg/dl)	9.7 ± 0.5	9.7 ± 0.4	9.5 ± 0.5	9.5 ± 0.4	0.25
Urinary calcium excretion (mg/d)	123 ± 83	81 ± 76	43 ± 39	28 ± 15	<0.001
25-hydroxyvitamin D (ng/ml)	29 ± 12	31 ± 14	28 ± 9	39 ± 14	0.04
1,25-dihydroxyvitamin D (pg/ml)	40 ± 18	39 ± 17	30 ± 13	33 ± 10	0.09
Parathyroid hormone (pg/ml)	47 (23, 69)	43 (23, 82)	68 (44, 128)	92 (62, 157)	0.01
Fibroblast growth factor 23 (RU/ml)	70 (37, 92)	98 (47, 118)	112 (55, 174)	118 (96, 154)	0.04