Determination of the upper cut-off values of serum alanine aminotransferase and aspartate aminotransferase in Chinese

Table 1 Potential factors affecting the levels of serum alanine aminotransferase and aspartate aminotransferase

Factors	ALT					AST
	Normal n = 3361	Abnormal n = 408	OR (95%CI)	Regression coefficients orχ2value	P value	Normal n = 3677	Abnormal n = 92	OR (95%CI)	Regression coefficients orχ2value	P value
Gender
Male	1506 (44.8)	292 (71.6)	1.0	342.1254	< 0.0001	1739 (47.3)	59 (64.1)	1.0	192.1106	< 0.0001
Female	1855 (55.2)	116 (28.4)	0.32 (0.26- 0.40)			1938 (52.7)	33 (35.9)	0.50 (0.33-0.77)
Age1	46 ± 19	43 ± 16	0.98 (0.98-0.99)	-0.09070	0.0017	45 ± 19	45 ± 16	1.00 (0.98-1.02)	0.03095	0.0891
Drinking
No	2220 (66.1)	198 (48.5)	1.0			2371 (64.5)	47 (51.1)	1.0
Previous	53 (1.6)	13 (3.2)	2.75 (1.47-5.13)	182.001	< 0.0001	65 (1.8)	1 (1.1)	0.78 (0.11-5.71)	120.0163	< 0.0001
Current	1088 (32.4)	197 (48.3)	2.03 (1.65-2.51)			1241 (33.8)	44 (47.8)	1.79 (1.18-2.71)
Smoking
No	2120 (63.1)	238 (58.3)	1.0	29.8714	< 0.0001	2295 (62.4)	63 (68.5)	1.0	9.9796	< 0.0001
Smoker	1241 (36.9)	170 (41.7)	1.22 (0.99-1.50)			1382 (37.6)	29 (31.5)	0.76 (0.49-1.19)
HBV
Negative	3234 (96.2)	365 (89.5)	1.0	55.4066	< 0.0001	3527 (95.9)	72 (78.3)	1.0	62.2821	< 0.0001
Positive	127 (3.8)	43 (10.5)	3.00 (2.09-4.31)			150 (4.1)	20 (21.7)	6.53 (3.88-11.01)
HCV
Negative	3330 (99.1)	399 (97.8)	1.0	10.4863	0.0012	3644 (99.1)	85 (92.4)	1.0	13.3629	0.0003
Positive	31 (0.9)	9 (2.2)	2.42 (1.15-5.13)			33 (0.9)	7 (7.6)	9.10 (3.91-21.14)
BMI	22.2 ± 3.91	23.67 ± 4.47	1.16 (1.13-1.20)	1.17256	< 0.0001	22.49 ± 3.70	22.81 ± 4.33	1.07 (1.00-1.14)	0.25393	0.0008
Cholesterol1	4.23 ± 1.2	4.57 ± 1.22	1.42 (1.28-1.56)	3.01080	< 0.0001	4.26 ± 1.20	4.50 ± 1.42	1.42 (1.19-1.70)	1.37468	< 0.0001
LDL1	2.90 ± 0.90	3.20 ± 0.90	1.37 (1.23-1.52)	2.56544	< 0.0001	3.00 ± 0.90	3.10 ± 1.10	1.23 (1.05-1.45)	1.16700	< 0.0001
HDL1	1.30 ± 0.40	1.30 ± 0.45	1.06 (0.90-1.25)	-0.36483	0.5918	1.30 ± 0.40	1.40 ± 0.60	1.24 (1.03- 1.50)	1.47788	0.0005
Triglyceride1	1.17 ± 0.97	1.76 ± 1.66	1.24 (1.17-1.30)	2.03651	< 0.0001	1.21 ± 1.05	1.51 ± 1.63	1.14 (1.07-1.22)	0.93710	< 0.0001

¹Data were expressed as median ± interquartile range in years; HBV positive was defined as HBsAg positive. ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; BMI: Body mass index.

Table 2 Comparison between the new cut-off values and the old standards in men

	Standard	Sensitivity (%)	Specificity (%)	P
ALT	Old	42.23	94.52	< 0.01
	New	88.76	84.55	< 0.01
AST	Old	40.21	95.53	< 0.01
	New	84.32	82.15	< 0.01

ALT: Alanine aminotransferase; AST: Aspartate aminotransferase.

Table 3 Upper normal limits of the levels of serum alanine aminotransferase and aspartate aminotransferase

Gender		Area	SE	P	Sensitivity	Specificity	Upper normal limit
Men	ALT	0.94	0.01	< 0.05	0.89	0.86	22.15
	AST	0.80	0.01	< 0.05	0.85	0.81	25.35
Women	ALT	0.90	0.006	< 0.05	0.90	0.82	22.40
	AST	0.84	0.008	< 0.05	0.85	0.80	24.25

ALT: Alanine aminotransferase; AST: Aspartate aminotransferase.

Table 4 Comparison between the new cut-off values and the old standards in women

	Standard	Sensitivity (%)	Specificity (%)	P
ALT	Old	58.12	96.52	< 0.01
	New	92.45	85.25	< 0.01
AST	Old	49.15	92.75	< 0.01
	New	84.62	80.34	< 0.01

ALT: Alanine aminotransferase; AST: Aspartate aminotransferase.