Table 1.
Baseline characteristics of 36,703 UK Biobank participants with quantified liver fat, stratified by presence of hepatic steatosis
| Steatosis absent (n = 30,453) | Steatosis present (n = 6,250) | p value | |
|---|---|---|---|
| Female | 16,540 (54.3%) | 2,509 (40.1%) | 1.07 × 10−92 |
| Age at enrollment, years | 54.9 (7.51) | 54.7 (7.23) | 0.004 |
| Age at imaging, years | 64.3 (7.62) | 63.8 (7.23) | 9.0 × 10−7 |
| Self-reported ethnicity | |||
| White | 29,527 (97.0%) | 6,045 (96.7%) | 0.36 |
| Black | 185 (0.6%) | 29 (0.5%) | 0.18 |
| South Asian | 239 (0.8%) | 74 (1.2%) | 0.002 |
| Other Asian | 138 (0.5%) | 27 (0.4%) | 0.82 |
| Multiple, other or not provided | 364 (1.2%) | 75 (1.2%) | 0.98 |
| Coronary artery diseasea | 1,030 (3.4%) | 253 (4.0%) | 0.009 |
| Diabetesa | 1,094 (3.6%) | 862 (13.8%) | 1.6 × 10−234 |
| Hypertensiona | 8,264 (27.1%) | 2,821 (45.1%) | 2.5 × 10−175 |
| Obesity | 3,964 (13.0%) | 2,531 (40.5%) | <1 × 10−300 |
| Medications | |||
| Anti-hypertensive therapy | 3,555 (11.7%) | 1,385 (22.2%) | 1.8 × 10−108 |
| Lipid-lowering therapy | 4,287 (14.1%) | 1,265 (20.2%) | 3.1 × 10−35 |
| Anthropometric data | |||
| Weight, kg | 74.7 (13.8) | 86.6 (15.3) | <1 × 10−300 |
| Waist-to-hip ratio | 0.85 (0.08) | 0.91 (0.08) | <1 × 10−300 |
| BMI, kg/m2 | 25.9 (3.8) | 29.7 (4.4) | <1 × 10−300 |
| Body fat, % | 29.4 (8.1) | 32.6 (8.1) | 3.1 × 10−136 |
| Estimated untreated systolic blood pressure, mmHg | 136 (19.2) | 136 (19.2) | 143 (18.8) |
| Alcohol consumption | |||
| Weekly drinks, United States standard | 5.4 (6.1) | 5.9 (7.7) | 0.02 |
| Weekly drinks, United Kingdom standard | 9.4 (10.6) | 10.4 (13.6) | 0.02 |
| Excessive alcohol intake, United States | 1,559 (5.1%) | 456 (7.3%) | 5.9 × 10−12 |
| Excessive alcohol intake, United Kingdom | 7,417 (24.4%) | 1,649 (26.4%) | 7.1 × 10−4 |
| Liver-associated biomarker concentrations | |||
| Alanine aminotransferase, IU/L | 21.3 (12.0) | 31.4 (18.9) | <1 × 10−300 |
| Aspartate aminotransferase, IU/L | 25.2 (9.9) | 28.7 (12.9) | 8.7 × 10−174 |
| Gamma glutamyltransferase, IU/L | 31.3 (31.3) | 45.6 (42.6) | <1 × 10−300 |
| Estimated untreated lipid concentrations | |||
| Total cholesterol, mg/dL | 226 (40.3) | 230 (42.3) | 1.5 × 10−11 |
| LDL cholesterol, mg/dL | 143 (31.7) | 150 (32.8) | 9.2 × 10−65 |
| HDL cholesterol, mg/dL | 58.5 (14.6) | 49.5 (11.6) | <1 × 10−300 |
| Triglycerides, mg/dL | 117 [85–169] | 176 [129–249] | <1 × 10−300 |
| Glycemic biomarker concentrations | |||
| Glycated hemoglobin, % | 5.3 (0.4) | 5.5 (0.6) | 1.4 × 10−128 |
| Glucose, mg/dL | 89.2 (16.0) | 93.4 (23.1) | 6.1 × 10−45 |
| Liver fat, % | 2.0 [1.5–2.9] | 9.9 [7.1–14.2] | <1 × 10−300 |
Liver fat was quantified in 36,703 UK Biobank participants from machine learning of MRI data using previous commercial vendor measurements in a subset of 4,511 individuals. Columns show participants grouped according to whether they had evidence of hepatic steatosis, defined as liver fat greater then 5.5%.17 Rows show measurements at the initial UK Biobank assessment visit, with values corresponding to number (%), mean (SD), or median [IQR]. p values correspond to unadjusted comparisons between presence or absence of steatosis, assessed via chi-square test or Wilcoxon rank-sum test (for categorical and continuous variables, respectively). Obesity was defined as BMI of 30 kg/m or greater.2,19 Excessive alcohol intake, United States was defined as alcohol intake exceeding American Association for the Study of Liver Disease guidelines for NAFLD definition.7 Excessive alcohol intake, United Kingdom was defined as alcohol intake exceeding the UK Chief Medical Officers’ recommendations.20 Estimated untreated lipid measurements and blood pressure were according to adjustments described previously.21,22 See also Tables S1 and S2.
Disease status assessed at time of MRI imaging visit.