Table 2.
Baseline characteristics by NAS*
| NAS ≤4 | NAS ≥5 | Total | P† | |
|---|---|---|---|---|
| N | 461 | 473 | 934 | |
| Age at biopsy - yrs (range) | 47.7 (18.3–78.5) |
48.1 (18.2–72.5) |
47.9 (18.2–78.5) |
0.56 |
| Female gender | 257 (55.8) | 320 (67.7) | 577 (61.8) | 0.0002 |
| Race | 0.74 | |||
| White | 368 (82.7) | 386 (85.0) | 754 (83.9) | |
| Black | 16 (3.6) | 12 (2.6) | 28 (3.1) | |
| Asian or Pac. Islander | 30 (6.7) | 23 (5.1) | 53 (5.9) | |
| Am Indian or AK Native | 13 (2.9) | 15 (3.3) | 28 (3.1) | |
| More than 1 race | 18 (4.0) | 18 (4.0) | 36 (4.0) | |
| Hispanic/Latino | 52 (11.3) | 63 (13.3) | 115 (12.3) | 0.34 |
| BMI (kg/m2) | 34.0 ± 6.5 | 34.3 ± 6.3 | 34.2 ± 6.4 | 0.51 |
| Diabetes (Type 2) | 108 (23.4) | 137 (29.0) | 245 (26.2) | 0.05 |
| ALT (U/L)‡ | 58 (36–78) | 82 (53–121) | 67 (46–98) | <0.0001 |
| Triglycerides (mg/dL) | 149 (105–202) | 161 (115–239) | 157 (110–219) | 0.007 |
| Glucose (mg/dL)‡ | 95 (86–107) | 96 (84–110) | 95 (85–108) | 0.85 |
| Insulin (µU/mL)‡ | 17.0 (11.5–24.0) | 20.1 (13.0–30.0) | 18.3 (12.1–28.2) | 0.001 |
| HOMA-IR‡ | 3.9 (2.6–6.3) | 4.8 (3.1–7.5) | 4.3 (2.8–7.0) | 0.004 |
| QUICKI‡ | 0.314 ± 0.032 | 0.307 ± 0.033 | 0.311 ± 0.032 | 0.008 |
| ANA positive‡ | 74 (24.8) | 66 (21.0) | 140 (22.9) | 0.26 |
*
Values are N (%), means ± SD, or medians (IQR), unless otherwise specified.
†
P-values derived from chi-square tests for categorical variables (Fisher’s Exact test when expected numbers were small), from ANOVA for age at biopsy and BMI, and from the Kruskal-Wallis Test for laboratory measures.
‡
Only laboratory values collected within 6 months of the liver biopsy were included. N=573 for ALT and glucose measurements; N=577 for triglycerides; N=563 for insulin and HOMA-IR measurements; N=612 for ANA. HOMA-IR is the homeostasis model assessment method for insulin resistance, calculated as (fasting insulin (µU/mL)*fasting glucose (mmol/L))/22.5. QUICKI is calculated as: 1/log(insulin µU/mL*glucose mg/dL).