Table 1. Study Sample Characteristics.
| Characteristic | Participants, No. (%)a | P Value | |
|---|---|---|---|
| No NAFLD (n = 629) |
NAFLD (n = 137) |
||
| Women | 351 (55.8) | 59 (43.1) | .007 |
| Age at covariate measurement, mean (SD), y | 59.5 (9.0) | 59.5 (8.5) | .93 |
| Age at CT scan, mean (SD) y | 63.8 (8.9) | 63.6 (8.6) | .88 |
| Age at MRI, mean (SD) y | 66.7 (8.9) | 66.9 (8.4) | .88 |
| Time between CT scan and covariate measurement, mean (SD), y | −4.2 (1.0) | −4.2 (1.0) | .56 |
| Time between CT scan and MRI, mean (SD), y | 3.0 (1.2) | 3.2 (1.3) | .03 |
| Educational level | |||
| <High school degree | 12 (1.9) | 4 (2.9) | .23 |
| High school degree | 147 (23.4) | 33 (24.1) | |
| Some college | 186 (29.6) | 50 (36.5) | |
| ≥College degree | 284 (45.2) | 50 (36.5) | |
| Postmenopausalb | 291 (82.9) | 49 (83.1) | .98 |
| Current smoker | 47 (7.5) | 12 (8.8) | .61 |
| Type 2 diabetes | 39 (6.2) | 19 (13.9) | .002 |
| History of cardiovascular disease | 55 (8.7) | 14 (10.2) | .58 |
| Body mass index, mean (SD)c | 27.3 (4.7) | 30.6 (5.5) | <.001 |
| Systolic blood pressure, mean (SD), mm Hg | 124 (18) | 126 (15) | .12 |
| Hypertension | 204 (32.4) | 65 (47.4) | .001 |
| Lipid treatment | 109 (17.3) | 20 (14.6) | .41 |
| Total cholesterol, mean (SD), mg/dL | 200 (36) | 198 (34) | .63 |
| LDL cholesterol, mean (SD), mg/dL | 122 (32) | 120 (31) | .55 |
| HDL cholesterol, mean (SD), mg/dL | 53 (16) | 47 (14) | <.001 |
| Triglycerides, median (25th-75th percentile), mg/dL | 104 (73-152) | 149 (101-203) | <.001 |
| Alcohol, median (25th-75th percentile), No. drinks/wk | 1.7 (0.0-3.3) | 1.7 (0.0-5.0) | .23 |
| Physical activity index score, mean (SD) | 37.6 (6.2) | 36.8 (5.7) | .13 |
| Visceral adipose tissue, mean (SD), cm3 | 1841 (983) | 2818 (1009) | <.001 |
| HOMA-IR, median (25th-75th percentile), mmol/L × μU/mL | 2.31 (1.71-3.36) | 3.82 (2.65-5.61) | <.001 |
| C-reactive protein, median (25th-75th percentile), mg/L | 1.70 (0.81-3.72) | 3.05 (1.38-5.90) | <.001 |
| Homocysteine, median (25th-75th percentile), mg/L | 1.00 (0.85-1.22) | 1.09 (0.91-1.28) | .02 |
| Alanine aminotransferase, median (25th-75th percentile), U/L | 18.0 (15.0-25.0) | 22.0 (16.0-34.0) | <.001 |
| Aspartate aminotransferase, median (25th-75th percentile), U/L | 21.0 (18.0-24.0) | 22.0 (18.0-27.0) | .06 |
| MRI brain measures | |||
| Total cerebral brain volume, mean (SD), %d | 79.4 (3.7) | 78.3 (3.6) | .002 |
| Hippocampal volume, median (25th-75th percentile), %d | 0.547 (0.051) | 0.552 (0.056) | .20 |
| White matter hyperintensities, median (25th-75th percentile), %d | 0.09 (0.05-0.18) | 0.10 (0.04-0.17) | .47 |
| Covert brain infarct | 85 (13.5) | 20 (14.6) | .74 |
Abbreviations: CT, computed tomographic; HDL, high-density lipoprotein; HOMA-IR, homeostatic model assessment of insulin resistance; LDL, low-density lipoprotein; MRI, magnetic resonance imaging; NAFLD, nonalcoholic fatty liver disease.
SI conversion factors: To convert total cholesterol, HDL cholesterol, and LDL cholesterol to millimoles per liter, multiply by 0.0259; to convert triglycerides to millimoles per liter, multiply by 0.0113; to convert C-reactive protein to nanomoles per liter, multiply by 9.524; to convert homocysteine to micromoles per liter, multiply by 7.397; and to convert alanine aminotransferase and aspartate aminotransferase to microkatals per liter, multiply by 0.0167.
Data are presented as number (percentage) of participants unless otherwise indicated.
Denominator is total number of women. Men were coded as nonmenopausal.
Calculated as weight in kilograms divided by height in meters squared.
Expressed as percentage of total cranial volume.