Association between serum alpha-fetoprotein levels and fatty liver disease: A cross-sectional study

Table 1 Comparison of clinical characteristics between the subjects with and without fatty liver disease

	Without FLD1	With FLD2	t value	P value
Age (yr)	45.0 (39.0–53.0)	48.0 (41.0–55.0)	8.248	< 0.001
Gender (male/female, n)	3748/3451	2132/469	712.0053	< 0.0013
Body mass index (kg/m2)	22.92 (2.71)	26.72 (2.72)	61.262	< 0.001
Waist circumference (cm)	80.4 (8.9)	92.7 (7.7)	58.903	< 0.001
Systolic blood pressure (mmHg)	123.8 (17.0)	134.9 (16.1)	29.053	< 0.001
Diastolic blood pressure (mmHg)	75.4 (10.9)	83.3 (10.5)	31.739	< 0.001
Alanine aminotransferase (U/L)	17.0 (13.0–24.0)	29.0 (21.0–43.0)	42.1944	< 0.0014
Aspartate aminotransferase (U/L)	20.0 (17.0–24.0)	23.0 (19.0–29.0)	25.3394	< 0.0014
Gamma-glutamyltransferase (U/L)	19.0 (13.0–31.0)	39.0 (25.0–64.0)	39.8464	< 0.0014
Direct bilirubin (μmol/L)	3.0 (2.0–4.0)	3.0 (2.0-4.0)	2.113	0.053
Indirect bilirubin (μmol/L)	9.0 (6.0–11.0)	9.0 (7.0–12.0)	4.7064	< 0.0014
Triglyceride (mmol/L)	1.10 (0.80–1.58)	1.92 (1.40–2.68)	41.7974	< 0.001
Total cholesterol (mmol/L)	4.75 (0.90)	5.08 (0.96)	15.839	< 0.001
HDL cholesterol (mmol/L)	1.19 (0.29)	1.02 (0.23)	26.529	< 0.001
LDL cholesterol (mmol/L)	2.54 (0.62)	2.63 (0.66)	6.19	< 0.001
Fasting blood glucose (mmol/L)	4.72 (4.44–5.02)	5.04 (4.67–5.56)	26.2504	< 0.0014
Serum uric acid (μmol/L)	317.7 (85.3)	390.8 (83.3)	37.671	< 0.001
Alpha-fetoprotein (μg/L)	2.90 (2.20–3.90)	3.10 (2.40–4.10)	7.6534	< 0.0014

¹n = 7199;

²n = 2601;

³χ² value;

⁴Z value. The data are expressed as the mean ± SD or median (interquartile range) depending on the data distribution. FLD: Fatty liver disease; HDL: High-density lipoprotein; LDL: Low-density lipoprotein.

Table 2 Correlations between alpha-fetoprotein and features of metabolic syndrome

	BMI	WC	SBP	DBP	TG	HDL-C	FBG
r value	0.101	0.17	0.11	0.135	0.17	-0.043	0.086
P value	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001

BMI: Body mass index; DBP: Diastolic blood pressure; FBG: Fasting blood glucose; HDL-C: High density lipoprotein cholesterol; SBP: Systolic blood pressure; TG: Triglyceride; WC: Waist circumference.

Table 3 Univariable analysis for factors associated with fatty liver disease

Variables	OR	95%CI	P value
Age (yr)	1.017	1.013-1.021	< 0.001
Male gender	4.185	3.748-4.672	< 0.001
Body mass index (kg/m2)	1.667	1.629-1.706	< 0.001
Waist circumference (cm)	1.187	1.177-1.197	< 0.001
Systolic blood pressure (mmHg)	1.038	1.035-1.041	< 0.001
Diastolic blood pressure (mmHg)	1.068	1.063-1.073	< 0.001
Alanine aminotransferase (U/L)	1.050	1.047-1.053	< 0.001
Aspartate aminotransferase (U/L)	1.039	1.033-1.045	< 0.001
Gamma-glutamyltransferase (U/L)	1.013	1.012-1.015	< 0.001
Direct bilirubin (μmol/L)	1.006	0.982-1.031	0.631
Indirect bilirubin (μmol/L)	1.020	1.010-1.030	< 0.001
Triglyceride (mmol/L)	1.992	1.898-2.091	< 0.001
Total cholesterol (mmol/L)	1.462	1.392-1.534	< 0.001
HDL cholesterol (mmol/L)	0.079	0.065-0.097	< 0.001
LDL cholesterol (mmol/L)	1.248	1.163-1.340	< 0.001
Fasting blood glucose (mmol/L)	1.828	1.724-1.938	< 0.001
Serum uric acid (μmol/L)	1.010	1.009-1.010	< 0.001
Alpha-fetoprotein (μg/L)	1.057	1.031-1.084	< 0.001

HDL: High-density lipoprotein; LDL: Low-density lipoprotein.

Table 4 Multivariable analysis for factors associated with fatty liver disease

Variables	OR	95%CI	P value
Age (yr)	1.011	1.004-1.018	0.003
Male gender	1.408	1.160-1.709	0.001
Body mass index (kg/m2)	1.268	1.218-1.321	< 0.001
Waist circumference (cm)	1.064	1.049-1.080	< 0.001
Diastolic blood pressure (mmHg)	1.020	1.014-1.027	< 0.001
Alanine aminotransferase (U/L)	1.043	1.036-1.051	< 0.001
Aspartate aminotransferase (U/L)	0.953	0.940-0.966	< 0.001
Triglyceride (mmol/L)	1.293	1.226-1.362	< 0.001
HDL cholesterol (mmol/L)	0.411	0.307-0.550	< 0.001
LDL cholesterol (mmol/L)	1.318	1.189-1.461	< 0.001
Fasting blood glucose (mmol/L)	1.338	1.251-1.430	< 0.001
Serum uric acid (μmol/L)	1.004	1.003-1.005	< 0.001

HDL: High-density lipoprotein; LDL: Low-density lipoprotein.