Table 2. Summary of the brain and cognitive outcome variables examined at the MRI phase (2012–2016).
| OVERVIEW (N = 542) | Mean (SD) |
|---|---|
| Age at MRI phase, years | 69.79 (5.22) |
| Years of education | 14.24 (3.01) |
| Years from Phase 9 to MRI phase | 5.90 (1.40) |
| Years from Phase 11 to MRI phase | 1.82 (1.36) |
| Years from Phase 9 to Phase 11 | 4.08 (0.18) |
| STRUCTURAL OUTCOMES (N = 542) | |
| GM volume, % ICV | 51.5 (4.2) |
| Global FA | 0.48 (0.02) |
| Global MD (× 10−3) | 0.69 (0.03) |
| Global RD (× 10−3) | 0.49 (0.03) |
| Global AD (× 10−3) | 1.08 (0.03) |
| WMLs, % ICVa | 0.53 (0.33) |
| CBF OUTCOMES (CBF, N = 112) | |
| Frontal lobe CBF (ml/100 g/min) | 51.37 (12.17) |
| Parietal lobe CBF (ml/100 g/min) | 62.06 (15.49) |
| Occipital lobe CBF (ml/100 g/min) | 49.04 (18.82) |
| Temporal lobe CBF (ml/100 g/min) | 49.35 (10.17) |
| COGNITIVE OUTCOMES (N = 537) | |
| Verbal learning (no. of words recalled, short term) | 27.81 (4.37) |
| Delayed verbal recall (no. of words recalled, delayed) | 9.45 (2.51) |
| Semantic fluency (no. of animals listed) | 22.51 (5.28) |
| Short-term memory (total digit span score) | 31.08 (5.47) |
| Executive function (Trail Making Test B-A, min) | 0.58 (0.44) |
| Executive function (digit substitution score) | 63.45 (13.05) |
| MoCA (total score) | 27.39 (2.10) |
aAnalysed WML subset (N = 533).
Values represent mean (SD). GM volume and WMLs are expressed as % of total intracranial volume.
AD, axial diffusivity; CBF, cerebral blood flow; FA, fractional anisotropy; GM, grey matter; ICV, intracranial volume; MD, mean diffusivity; MoCA, Montreal Cognitive Assessment; MRI, magnetic resonance imaging; RD, radial diffusivity; SD, standard deviation; WML, white matter lesion.