Table 2.

Age- and gender-specific reference intervals for 8 liver function tests in healthy children aged 2–14 years (n = 1394)

Analytes	Age group (y)	Sex group	No. of samples	Lower limit	Upper limit	Confidence interval for lower limit	Confidence interval for upper limit
ALT (U/L)	2	F + M	196	8	24	7–9	22–26
	3 to < 6	F + M	663	7	23	6–7	21–24
	7 to < 10	F + M	275	4	19	3–4	16–22
	11 to < 14	F	113	5	25	4–6	15–33
		M	147	5	35	4–6	31–37
AST (U/L)	2	F + M	196	27	49	25–29	45–53
	3 to < 5	F + M	560	22	44	20–24	42–45
	6	F + M	103	18	40	16–21	38–42
	7 to < 12	F	192	11	35	10–12	31–38
		M	202	13	39	10–16	33–42
	13 to < 14	F	59	14	26	13–15	18–28
		M	82	13	36	13–15	26–40
GGT (U/L)	2 to < 4	F + M	603	8	16	7–8	15–17
	5 to < 10	F + M	530	8	21	7–9	19–22
	11 to < 14	F	113	8	29	7–9	17–41
		M	147	10	43	9–11	35–51
ALP (U/L)	2 to < 3	F + M	452	160	376	153–169	355–390
	4 to < 9	F + M	587	143	362	134–153	354–370
	10 to < 12	F + M	213	116	426	99–136	354–471
	13 to < 14	F	56	48	232	42–58	149–243
		M	85	111	486	92–148	338–512
TP (g/L)	2 to < 3	F + M	452	59.5	74.4	59.1–60.1	72.9–75.3
	4 to < 6	F + M	407	59.2	76.4	57.2–61.2	75.6–77.3
	7 to < 10	F + M	275	62.5	78.2	59.1–64.1	76.2–80.2
	11 to < 14	F + M	260	63.6	79.2	61.5–66.1	77.4–80.8
ALB (g/L)	2 to < 10	F + M	1134	40.0	52.3	39.7–40.5	51.9–52.7
	11 to < 14	F + M	260	41.3	53.1	39.3–43.5	52.5–53.5
TBIL (µmol/L)	2 to < 3	F + M	451	3.0	13.0	2.8–3.2	11.9–13.7
	4 to < 7	F + M	481	3.4	14.8	3.2–3.8	13.9–15.7
	8 to < 14	F + M	455	4.5	16.6	4.0–5.0	15.6–17.6
DBIL (µmol/L)	2 to < 3	F + M	451	0.9	3.3	0.8–1.0	3.1–3.5
	4 to < 7	F + M	481	1.1	3.8	1.0–1.2	3.5–3.9
	8 to < 12	F + M	316	1.6	4.5	1.5–1.8	4.1–4.9
	13 to < 14	F + M	139	1.2	5.3	0.8–1.6	4.8–5.9

ALT alanine aminotransferase, AST aspartate aminotransferase, GGT γ-glutamyltransferase, ALP alkaline phosphatase, TP total protein, ALB albumin, TBIL total bilirubin, DBIL direct bilirubin, M male, F female