Machine learning models for predicting non-alcoholic fatty liver disease in the general United States population: NHANES database

Table 1 Baseline characteristics of participants in training and testing data

	Training data (n = 2265)	Testing data (n = 970)	P value
Demographic
Age (yr)	43 (29)	43.5 (28)	0.328
Gender (male) (%)	944 (41.68)	428 (44.12)	0.197
Race/ethnicity
White (non-Hispanic) (%)	959 (42.34)	392 (40.41)	0.308
Black (non-Hispanic) (%)	627 (27.68)	271 (27.94)	0.882
Mexican American (%)	576 (25.43)	254 (26.19)	0.652
Others (%)	103 (4.55)	53 (5.46)	0.265
Body measurement
Body mass index (kg/m2)	26.4 (7.2)	26.7 (7.4)	0.120
Waist circumference (cm)	93 (20.5)	93.5 (20.8)	0.182
Biochemistry tests
Iron (ug/dL)	73 (39)	74 (39)	0.098
Total iron-binding capacity (ug/dL)	355 (72)	356 (72)	0.450
Transferrin saturation (%)	20.5 (11.1)	20.8 (11.8)	0.329
Ferritin (ng/mL)	87 (125)	84.5 (124)	0.508
Cholesterol (mg/dL)	201 (57)	204 (59)	0.155
Triglyceride (mg/dL)	120 (100.25)	122.5 (102)	0.562
HDL cholesterol (mg/dL)	48 (18)	48.5 (18)	0.585
C-reactive protein (mg/dL)	0.21 (0.29)	0.21 (0.23)	0.686
Uric acid (mg/dL)	5 (1.9)	5.1 (2)	0.427
Liver chemistry
Aspartate aminotransferase (U/L)	19 (8)	19 (7)	0.908
Alanine aminotransferase (U/L)	14 (10)	14 (10)	0.581
Gamma glutamyl transferase (U/L)	21 (18)	21 (18)	0.787
Alkaline phosphatase (U/L)	83 (33)	81 (32)	0.524
Total bilirubin (mg/dL)	0.5 (0.2)	0.5 (0.2)	0.855
Total protein (g/dL)	7.4 (0.6)	7.4 (0.6)	0.559
Albumin (g/dL)	4.1 (0.5)	4.1 (0.4)	0.543
Serum globulin (g/dL)	3.3 (0.6)	3.3 (0.7)	0.941
Diabetes testing profile
Glycated hemoglobin (%)	5.4 (0.8)	5.4 (0.7)	0.075
Fasting plasma glucose (mg/dL)	91.6 (12.52)	92.05 (12.2)	0.726
Fasting C-peptide (pmol/mL)	0.65 (0.68)	0.66 (0.69)	0.746
Fasting insulin (uU/mL)	9.36 (9.51)	9.73 (10.04)	0.378
Diabetes medication	165 (7.28%)	68 (7.01%)	0.782