Table 4.

Creatinine and cystatin levels according to age and GFR

	Less than 10 Years	Between 10 and 15 Years	More than 15 Years	P
In children with inulin clearance ≥90 ml/min per 1.73 m2
n	105	37	27
body weight (kg)	24 ± 5	38 ± 10	55 ± 11	<0.001
height (cm)	122 ± 9	146 ± 11	163 ± 12	<0.001
plasma creatinine (μmol/L)	36 ± 8	45 ± 13	57 ± 13	<0.001
serum cystatin C (mg/L)	0.74 ± 0.13	0.76 ± 0.13	0.73 ± 0.12	NS
inulin clearance (ml/min per 1.73 m2)	118 ± 22	117 ± 20	119 ± 22	NS
eGFR Schwartz 2009 (ml/min per 1.73 m2)	130 ± 37a	131 ± 57	110 ± 24a	0.01
correlation coefficient between Schwartz 2009 and iGFR	0.417b	0.571b	0.546b
eGFR local Schwartz (ml/min per 1.73 m2)	117 ± 33	120 ± 52	105 ± 21a	NS
correlation coefficient between local Schwartz and iGFR	0.418b	0.631b	0.548b
eGFR Larsson (ml/min)	117 ± 26	114 ± 25	119 ± 25	NS
correlation coefficient between Larsson and iGFR	0.367b	0.487b	0.739b
eGFR Le Bricon (ml/min per 1.73 m2)	112 ± 19a	110 ± 18a	114 ± 18	NS
correlation coefficient between Le Bricon and iGFR	0.367b	0.487b	0.739b
In children with inulin clearance <90 ml/min per 1.73 m2
n	28	29	26
body weight (kg)	24 ± 4	41 ± 13	56 ± 7	<0.001
height (cm)	122 ± 8	148 ± 10	163 ± 8	<0.001
plasma creatinine (μmol/L)	62 ± 28	77 ± 25	109 ± 36	<0.001
serum cystatin C (mg/L)	1.15 ± 0.42	1.29 ± 0.39	1.30 ± 0.45	NS
inulin clearance (ml/min per 1.73 m2)	70 ± 17	63 ± 16	63 ± 18	NS
eGFR Schwartz 2009 (ml/min per 1.73 m2)	79 ± 18a	77 ± 23a	61 ± 20	0.004
correlation coefficient between Schwartz 2009 and iGFR	0.834b	0.842b	0.781b
eGFR local Schwartz (ml/min per 1.73 m2)	71 ± 16	72 ± 21a	58 ± 18	0.011
correlation coefficient between local Schwartz and iGFR	0.837b	0.839b	0.821b
eGFR Larsson (ml/min)	72 ± 20	62 ± 20	65 ± 29	NS
correlation coefficient between Larsson and iGFR	0.553b	0.822b	0.872b
eGFR Le Bricon (ml/min per 1.73 m2)	77 ± 17a	69 ± 17a	71 ± 24a	NS
correlation coefficient between Le Bricon and iGFR	0.553b	0.822b	0.872b

^aP < 0.05, Wilcoxon paired test in comparison with inulin clearance.

^bP < 0.001, Spearman correlation.