C-peptide as a key risk factor for non-alcoholic fatty liver disease in the United States population

Table 2 Univariate analysis for predictors of non-alcoholic fatty liver disease

	Beta	Standard error	Odds ratio	P value
Demographic
Age (yr)	0.0157	0.0025	1.02	< 0.001a
Gender (male)	0.1435	0.0815	1.15	0.078
Race/ethnicity
White (non-Hispanic)	-0.226	0.0831	0.80	0.007a
Black (non-Hispanic)	-0.2857	0.0937	0.75	0.002a
Mexican American	0.5715	0.0882	1.77	< 0.001a
Others	-0.1248	0.1945	0.88	0.521
Body measurement
Body mass index (kg/m2)	0.1004	0.0069	1.11	< 0.001a
Waist circumference (cm)	0.0506	0.003	1.05	< 0.001a
Biochemistry tests
Iron (μg/dL)	-0.0024	0.0013	1.00	0.069
TIBC (μg/dL)	0.0015	0.0007	1.00	0.032a
Transferrin saturation (%)	-0.0111	0.0044	0.99	0.012a
Ferritin (ng/mL)	0.0029	0.0003	1.00	< 0.001a
Cholesterol (mg/dL)	0.005	0.0009	1.01	< 0.001a
Triglyceride (mg/dL)	0.0049	0.0004	1.00	< 0.001a
HDL cholesterol (mg/dL)	-0.0261	0.0031	0.97	< 0.001a
C-reactive protein (mg/dL)1	0.3398	0.0534	1.40	< 0.001a
Uric acid (mg/dL)	0.2649	0.0277	1.30	< 0.001a
Liver chemistry
AST (U/L)1	1.004	0.1153	1.02	< 0.001a
ALT (U/L)1	1.0274	0.0777	1.04	< 0.001a
GGT (U/L)1	0.7441	0.0612	1.01	< 0.001a
ALP (U/L)1	0.9011	0.1303	1.01	< 0.001a
Total bilirubin (mg/dL)	0.0914	0.1395	1.09	0.512
Total protein (g/dL)	0.581	0.0896	1.79	< 0.001a
Albumin (g/dL)	-0.0871	0.1141	0.92	0.445
Diabetes testing profile
HbA1c (%)1	2.2201	0.2184	1.34	< 0.001a
FPG (mg/dL)1	1.3125	0.1428	1.01	< 0.001a
Fasting C-peptide (pmol/mL)	1.1976	0.0753	3.31	< 0.001a
Fasting insulin (μU/mL)1	0.9646	0.059	1.02	< 0.001a

¹Log transformation was applied to this factor before including in regression model.

^aP < 0.05. ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; FPG: Fasting plasma glucose; GGT: Gamma glutamyl transferase; HbA1c: Glycated hemoglobin; TIBC: Total iron-binding capacity. ^aP < 0.05.