Lower alanine aminotransferase levels are associated with increased all-cause and cardiovascular mortality in nonalcoholic fatty liver patients

Table 1 Baseline characteristics of the overall population and nonalcoholic fatty liver disease patients with normal or elevated alanine aminotransferase level

	Overall population (n = 11441)			NAFLD population (n = 4159)
	Normal ALT level (n = 9698)	Elevated ALT level (n = 1743)	P value	Normal ALT level (n = 3131)	Elevated ALT level (n = 1028)	P value
Age (yr)	44.4 ± 0.17	41.5 ± 0.35	< 0.001	48.0 ± 0.29	43.2 ± 0.45	< 0.001
Sex, male (%)	4397 (45.3)	710 (40.7)	< 0.001	1496 (47.8)	436 (42.4)	0.003
Race/ethnicity, n (%)			< 0.001			< 0.001
Non-Hispanic White	3725 (38.4)	527 (30.2)		1186 (37.9)	300 (29.2)
Non-Hispanic Black	2950 (30.4)	325 (18.6)		861 (27.5)	143 (13.9)
Mexican American	2620 (27.0)	815 (46.8)		967 (30.9)	540 (52.5)
Others	403 (4.2)	76 (4.4)		117 (3.7)	45 (4.4)
Waist circumference (cm)	92.3 ± 0.15	98.3 ± 0.35	< 0.001	97.9 ± 0.30	102.6 ± 0.45	< 0.001
BMI (kg/m2)	27.0 ± 0.06	29.7 ± 0.15	< 0.001	28.9 ± 0.12	31.4 ± 0.20	< 0.001
Hypertension, n (%)	3892 (40.1)	698 (40.0)	0.946	1434 (45.8)	458 (44.6)	0.486
Diabetes, n (%)	836 (8.6)	253 (14.5)	< 0.001	476 (15.2)	214 (20.8)	< 0.001
HOMA-IR, n (%)	3652 (37.7)	1117 (64.1)	< 0.001	1712 (54.7)	785 (76.4)	< 0.001
Fasting plasma glucose (mmol/L)	5.6 ± 0.02	5.9 ± 0.06	< 0.001	6.0 ± 0.05	6.3 ± 0.09	0.002
HbA1c (%)	5.5 ± 0.01	5.7 ± 0.03	< 0.001	5.8 ± 0.02	5.9 ± 0.05	0.027
TG (mg/dL)	135.2 ± 1.0	182.4 ± 3.2	< 0.001	165.9 ± 2.09	207.0 ± 4.49	< 0.001
Total cholesterol (mg/dL)	204.2 ± 0.44	209.7 ± 1.07	< 0.001	208.6 ± 0.80	212.6 ± 1.37	< 0.001
HDL (mg/dL)	51.3 ± 0.15	47.0 ± 0.36	< 0.001	48.3 ± 0.27	45.0 ± 0.47	< 0.001
ALT (IU/L)	13.7 ± 0.06	39.5 ± 0.63	< 0.001	14.9 ± 0.10	41.7 ± 0.90	< 0.001
AST (IU/L)	19.0 ± 0.06	34.2 ± 0.64	< 0.001	19.5 ± 0.11	35.6 ± 0.92	< 0.001
Albumin (g/L)	41.4 ± 0.04	41.7 ± 0.09	0.007	41.1 ± 0.07	41.8 ± 0.11	< 0.001
Smoked at least 100 cigarettes, n (%)	4872 (50.2)	752 (43.3)	< 0.001	1637 (52.3)	448 (43.6)	< 0.001
Sedentary lifestyle, n (%)	2811 (29.0)	583 (33.4)	< 0.001	1048 (33.5)	373 (36.3)	0.099
NAFLD, n (%)	3131 (32.3)	1028 (59.0)	< 0.001
Mild	1326 (13.7)	229 (13.1)		1326 (42.4)	229 (22.3)
Moderate	1268 (13.1)	490 (28.1)		1268 (40.5)	490 (47.7)
Severe	537 (5.5)	309 (1.7)	< 0.001	537 (17.2)	309 (30.1)	< 0.001

Categorical values are shown as n (%). Continuous variables are shown as mean ± SEs. Elevated alanine aminotransferase (ALT) level was defined as ALT > 30 U/L in men or > 19 U/L in women. BMI: Body mass index; HOMA-IR: Homeostasis model assessment of insulin resistance; HbA1c: Glycosylated hemoglobin; TG: Triglyceride; HDL: High-density lipoprotein cholesterol; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; NAFLD: Nonalcoholic fatty liver disease.