Table 1. Selected characteristics of the study participants, according to NAFLD prevalence; NHANES, 2001 – 2006*.
| Controls (n = 8,340) |
NAFLD Cases (n = 2,058) |
P- value£ |
|
|---|---|---|---|
| Age (yrs.) | 44.8 ± 0.2 | 43.2 ± 0.3 | < 0.01 |
| Men (%) | 39.8 ± 0.5 | 66.2 ± 1.0 | < 0.01 |
| Race or ethnicity (%) | |||
| Mexican-American | 21.4 ± 0.4 | 30.4 ± 1.0 | < 0.01 |
| Other Hispanic | 3.5 ± 0.2 | 5.3 ± 0.5 | |
| Non-Hispanic White | 48.6 ± 0.5 | 45.5 ± 1.1 | |
| Non-Hispanic Black | 22.4 ± 0.5 | 15.0 ± 0.8 | |
| Other | 4.1 ± 0.2 | 3.7 ± 0.4 | |
| Annual household income (%) | |||
| ≤ $15,000 | 13.9 ± 0.4 | 11.9 ± 0.7 | 0.03 |
| $15,001 – $25,000 | 15.1 ± 0.4 | 14.4 ± 0.8 | |
| > $25,000 | 71.0 ± 0.5 | 73.7 ± 1.0 | |
| Education (%) | |||
| ≤ 8 years | 11.4 ± 0.3 | 14.8 ± 0.8 | < 0.01 |
| 9 – 12 years | 15.2 ± 0.4 | 14.9 ± 0.8 | |
| > 12 years | 73.3 ± 0.5 | 70.3 ± 1.0 | |
| Body mass index (kg/m2) | 28.5 ± 0.1 | 30.3 ± 0.1 | < 0.01 |
| Waist circumference (cm) | 96.7 ± 0.2 | 102.3 ± 0.3 | < 0.01 |
| Physical activity (Sedentary) (%) | 23.3 ± 0.5 | 21.6 ± 0.9 | 0.10 |
| Smoking status (%) | |||
| Never smokers | 54.8 ± 0.5 | 53.6 ± 1.1 | 0.07 |
| Former smokers | 23.0 ± 0.5 | 25.4 ± 1.0 | |
| Current smokers | 22.1 ± 0.5 | 21.0 ± 0.9 | |
| Diabetes†(%) | 9.9 ± 0.3 | 8.6 ± 0.6 | 0.09 |
| Hypertension†(%) | 28.2 ± 0.5 | 28.6 ± 1.0 | 0.78 |
| Hypercholesterolaemia†(%) | 39.3 ± 0.7 | 44.9 ± 1.4 | < 0.01 |
| Insulin resistance ¥ (%) | 32.0 ± 0.7 | 56.2 ± 1.6 | < 0.01 |
| Glycated hemoglobin (%) | 5.5 ± 0.01 | 5.7 ± 0.02 | < 0.01 |
| Systolic BP (mm Hg) | 122.0 ± 0.2 | 123.3 ± 0.4 | < 0.01 |
| Diastolic BP (mm Hg) | 70.0 ± 0.1 | 72.9 ± 0.3 | < 0.01 |
| Serum triglycerides (mmol/L) | 1.6 ± 0.02 | 2.1 ± 0.06 | < 0.01 |
| Serum total cholesterol (mmol/L) | 5.2 ± 0.01 | 5.4 ± 0.03 | < 0.01 |
| Serum LDL-cholesterol (mmol/L) | 3.0 ± 0.01 | 3.2 ± 0.04 | < 0.01 |
| Serum HDL cholesterol (mmol/L) | 1.4 ± 0.005 | 1.2 ± 0.008 | < 0.01 |
| Serum alanine aminotransferase (U/L) |
19.4 ± 0.1 | 47.0 ± 1.0 | < 0.01 |
| Serum aspartate aminotransferase (U/L) |
21.4 ± 0.1 | 35.9 ± 0.5 | < 0.01 |
| Serum γ-glutamyltransferase (U/L) | 21.8 ± 0.2 | 48.4 ± 1.5 | < 0.01 |
| Serum uric acid (μmol/L) | 303.1 ± 0.9 | 345.7 ± 1.9 | < 0.01 |
| PPIs use (%) | 6.1 ± 0.3 | 6.4 ± 0.5 | 0.59 |
| H2RAs use (%) | 1.8 ± 0.1 | 1.7 ± 0.3 | 0.91 |
| H1RAs use (%) | 3.4 ± 0.2 | 2.7 ± 0.4 | 0.14 |
*
Values are percentages ± standard errors (SE) for categorical variables and means ± SE for continuous variables
£
From Student t-test for continuous variables and chi square test for categorical variables
†
Self-reported doctor diagnosis and medication use
¥
Insulin resistance was defined as a homeostasis of model assessment score, or HOMA, > 3.0