Table 2.
Descriptive statistics and factor loadings for brain measurements
| Measured variable | Wave 2 (age 73) | Wave 3 (age 76) | |||
|---|---|---|---|---|---|
| n | M (SD) | Factor loading | n | M (SD) | |
| Grey matter volume (cm3) | 657 | 472.43 (44.68) | – | 461 | 465.67 (43.61) |
| White matter volume (cm3) | 657 | 476.89 (50.55) | – | 461 | 464.25 (53.09) |
| White matter hyperintensity volume (cm3) | 656 | 12.23 (12.18) | – | 464 | 15.85 (14.57) |
| Corpus callosum genu FA | 646 | 0.41 (0.05) | 0.602 | 438 | 0.38 (0.04) |
| Corpus callosum splenium FA | 663 | 0.49 (0.07) | 0.338 | 437 | 0.51 (0.07) |
| L arcuate fasciculus FA | 639 | 0.45 (0.04) | 0.648 | 455 | 0.43 (0.04) |
| R arcuate fasciculus FA | 580 | 0.43 (0.04) | 0.613 | 414 | 0.41 (0.04) |
| L anterior thalamic radiation FA | 556 | 0.32 (0.03) | 0.642 | 429 | 0.33 (0.03) |
| R anterior thalamic radiation FA | 643 | 0.33 (0.03) | 0.657 | 453 | 0.34 (0.03) |
| L rostral cingulum FA | 641 | 0.44 (0.05) | 0.596 | 448 | 0.44 (0.05) |
| R rostral cingulum FA | 650 | 0.39 (0.04) | 0.551 | 448 | 0.41 (0.05) |
| L uncinate fasciculus FA | 567 | 0.33 (0.03) | 0.680 | 407 | 0.34 (0.03) |
| R uncinate fasciculus FA | 628 | 0.33 (0.03) | 0.670 | 443 | 0.33 (0.03) |
| L inferior longitudinal fasciculus FA | 663 | 0.40 (0.05) | 0.510 | 455 | 0.39 (0.06) |
| R inferior longitudinal fasciculus FA | 664 | 0.38 (0.05) | 0.480 | 462 | 0.38 (0.05) |
| Corpus callosum genu MD | 646 | 770.05 (66.05) | 0.659 | 438 | 850.28 (82.99) |
| Corpus callosum splenium MD | 663 | 978.47 (173.32) | - | 437 | 852.01 (153.16) |
| L arcuate fasciculus MD | 639 | 659.50 (47.60) | 0.686 | 455 | 699.45 (58.14) |
| R arcuate fasciculus MD | 580 | 646.35 (52.29) | 0.715 | 414 | 681.46 (58.21) |
| L anterior thalamic radiation MD | 556 | 758.24 (66.00) | 0.653 | 429 | 795.90 (66.85) |
| R anterior thalamic radiation MD | 643 | 754.29 (62.44) | 0.738 | 453 | 791.45 (86.75) |
| L rostral cingulum MD | 641 | 648.13 (45.64) | 0.557 | 448 | 673.84 (46.71) |
| R rostral cingulum MD | 650 | 651.92 (45.08) | 0.618 | 448 | 663.39 (42.12) |
| L uncinate fasciculus MD | 567 | 770.37 (53.82) | 0.643 | 407 | 794.30 (57.22) |
| R uncinate fasciculus MD | 628 | 756.31 (52.30) | 0.703 | 443 | 796.54 (58.11) |
| L inferior longitudinal fasciculus MD | 663 | 771.85 (100.10) | 0.426 | 455 | 826.54 (143.47) |
| R inferior longitudinal fasciculus MD | 664 | 772.20 (101.48) | 0.414 | 462 | 801.15 (122.90) |
Factor loadings were invariant across waves. The splenium had a low loading for MD and so was not included in the general factor
FA fractional anisotropy; MD mean diffusivity; L/R left/right hemisphere