Table 3. Differences in TCBV and Correspondent Years of Brain Aging by Age Groups.
Age Group, y | No. | Mean TCBV, Adjusted for Age Group, % of Total Cranial Volume | Years of Brain Aging Due to NAFLDa | |
---|---|---|---|---|
No NAFLD | NAFLD | |||
<60 | 174 | 82.3 | 80.4 | 7.3 |
60-74 | 429 | 79.7 | 78.6 | 4.2 |
≥75 | 163 | 75.6 | 75.2 | 1.5 |
All participants | 766 | 79.4 | 78.3 | 4.2 |
Abbreviations: NAFLD, nonalcoholic fatty liver disease; TCBV, total cerebral brain volume.
Calculation of years of brain aging is based on regressing TCBV onto age at magnetic resonance imaging, where the slope is the estimate of the change in TCBV per year of age (β, –0.26 cm3/y of age). Mean TCBV specific to age groups (<60, 60-74, and ≥75 y) was calculated for those with and without NAFLD. For each age group, the difference between the mean TCBV among those with and without NAFLD divided by the β coefficient yields the years of brain aging due to NAFLD.