Table 1.
Clinical characteristics of the study sample.
| Variable | Total (N=1656) | MCIa (n=23) | NCb (n=1633) | |
| Age (years), mean (SD) | 61 (13) | 78 (7) | 61 (13) | |
| Women, n (%) | 843 (50.9) | 14 (60.9) | 829 (50.8) | |
| Education, n (%) |
|
|
|
|
|
|
No high school | 187 (11.3) | 3 (13.0) | 184 (11.3) |
|
|
High school | 319 (19.3) | 6 (26.1) | 313 (19.2) |
|
|
Some college | 440 (26.6) | 3 (13.0) | 437 (26.8) |
|
|
College and higher | 710 (42.9) | 11 (47.8) | 699 (42.8) |
| MRIc measuresd, mean (SD) |
|
|
|
|
|
|
Total cerebral cranial volume (cm3) | 1251 (129) | 1252 (104) | 1251 (129) |
|
|
Total cerebral brain volume (%) | 77.0 (2.9) | 72.8 (2.5) | 77.0 (2.9) |
|
|
Cerebral white matter volume (%) | 36.3 (2.4) | 34.3 (2.7) | 36.3 (2.4) |
|
|
Cerebral gray matter volume (%) | 40.4 (2.1) | 37.4 (2.2) | 40.4 (2.1) |
|
|
Hippocampal volume (%) | 0.54 (0.05) | 0.50 (0.05) | 0.54 (0.05) |
|
|
Log (white matter hyperintensity volume) (%) | −2.33 (1.48) | −0.59 (1.38) | −2.35 (1.47) |
| Neuropsychological test scores, mean (SD) |
|
|
|
|
|
|
LMie | 13 (3) | 10 (4) | 13 (3) |
|
|
LMde | 12 (4) | 8 (4) | 12 (4) |
|
|
LMre | 10 (1) | 9 (2) | 10 (1) |
|
|
VRif | 9 (3) | 5 (2) | 9 (3) |
|
|
VRdf | 8 (3) | 3 (3) | 8 (3) |
|
|
VRrf | 3 (1) | 2 (1) | 3 (1) |
|
|
PASig | 15 (3) | 11 (3) | 15 (3) |
|
|
PASdg | 9 (1) | 7 (2) | 9 (1) |
|
|
PASrg | 10 (1) | 9 (2) | 10 (1) |
|
|
DSfh | 7 (1) | 6 (1) | 7 (1) |
|
|
DSbh | 5 (1) | 4 (1) | 5 (1) |
|
|
Trails Ai (s) | 31 (13) | 44 (14) | 31 (13) |
|
|
Trails Bi (s) | 83 (65) | 219 (159) | 82 (61) |
|
|
Similarities | 17 (3) | 14 (5) | 17 (3) |
|
|
Hooper Visual Organization Test | 26 (3) | 23 (4) | 26 (3) |
|
|
Boston Naming Test—30 item version | 26 (7) | 24 (7) | 26 (7) |
|
|
FASj | 41 (12) | 32 (12) | 41 (12) |
|
|
FAS-Animalj | 19 (6) | 15 (5) | 19 (6) |
aMCI: mild cognitive impairment.
bNC: normal cognition.
cMRI: magnetic resonance imaging.
dAll MRI measures were corrected for head size by calculating the percentage of the volumes over the total cerebral cranial volume above the tentorium. The percentage of white matter hyperintensity volume/total cerebral cranial volume was log transformed.
eWechsler Memory Scale Logical Memory—Immediate Recall (LMi), Delayed Recall (LMd), and Recognition (LMr).
fVisual Reproduction—Immediate Recall (VRi), Delayed Recall (VRd), and Recognition (VRr).
gPaired Associate Learning—Immediate Recall (PASi), Delayed Recall (PASd), and Recognition (PASr).
hWechsler Adult Intelligence Scale Digit Span—Forward (DSf) and Backward (DSb).
iTrail Making Test A (Trails A) and B (Trails B).
jVerbal fluency test (FAS and FAS-Animal).