Table 2.
Pairwise correlations between continuous covariates, predictors, and outcome variables
| Sex | Education (years) | LPA (min) | MVPA (min) | SB (min) | Sleep (min) | Total GM vol | Temporal vol | Hippocamp. vol | Ventricle vol | Frontal lobe vol | Processing speed | Executive function | Long-term memory | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age (years) |
-0.10 (-0.20,-0.00) |
0.01 (-0.09, 0.11) |
0.05 (-0.05, 0.15) |
-0.08 (-0.18, 0.02) |
-0.00 (-0.11, 0.10) |
0.03 (-0.07, 0.14) |
-0.28 (-0.37, -0.19) |
-0.20 (-0.29, -0.10) |
-0.16 (-0.25, -0.06) |
0.21 (0.11, 0.30) |
-0.10 (-0.20, 0.00) |
-0.14 (-0.24, -0.04) |
-0.26 (-0.35, -0.16) |
-0.07 (-0.25, 0.03) |
| Sex |
-0.07 (-0.17, 0.03) |
0.03 (-0.07, 0.13) |
-0.20 (-0.30, -0.10) |
0.00 (-0.10, 0.10) |
0.14 (0.04, 0.23) |
0.02 (-0.08, 0.12) |
-0.01 (-0.11, 0.09) |
-0.08 (-0.18, 0.02) |
-0.01 (0.11, 0.09) |
0.12 (0.02, 0.22) |
0.01 (-0.10, 0.10) |
-0.17 (-0.27, -0.07) |
0.06 (-0.04, 0.16) |
|
| Education (years) |
-0.05 (-0.15, 0.05) |
-0.01 (-0.11, 0.09) |
0.09 (-0.01, 0.19) |
-0.10 (-0.20, 0.00) |
0.05 (-0.05, 0.15) |
0.03 (-0.07, 0.13) |
0.02 (-0.08, 0.12) |
-0.03 (-0.13, 0.08) |
0.02 (-0.08, 0.12) |
-0.01 (-0.12, 0.09) |
0.12 (0.02, 0.22) |
0.08 (-0.02, 0.19) |
||
| LPA (min) |
0.29 a (0.19, 0.38) |
0.06a (-0.04, 0.16) |
0.10 a (0.00, 0.19) |
-0.04 (-0.14, 0.06) |
-0.04 (-0.14, 0.06) |
-0.00 (-0.10, 0.10) |
0.02 (-0.07, 0.13) |
-0.01 (-0.11, 0.09) |
0.07 (-0.03, 0.18) |
-0.05 (-0.15, 0.06) |
0.02 (-0.09, 0.12) |
|||
| MVPA (min) |
-0.67 a (-0.73, -0.59) |
-0.55 a (-0.63, -0.46) |
0.04 (-0.06, 0.14) |
0.05 (-0.05, 0.15) |
0.06 (-0.04, 0.16) |
-0.05 (-0.15, 0.05) |
-0.07 (-0.17, 0.03) |
0.18 (0.07, 0.27) |
0.02 (-0.08, 0.12) |
0.05 (-0.05, 0.15) |
||||
| SB (min) |
0.81 a (0.77, 0.85) |
-0.02 (-0.12, 0.08) |
-0.02 (-0.12, 0.08) |
-0.00 (-0.10, 0.10) |
0.01 (-0.09, 0.11) |
0.07 (-0.03, 0.17) |
-0.14 (-0.24, -0.04) |
0.01 (-0.09, 0.12) |
0.04 (-0.06, 0.14) |
|||||
| Sleep (min) |
0.04 (-0.06, 0.14) |
0.03 (-0.08, 0.13) |
-0.04 (-0.14, 0.06) |
0.00 (-0.10, 0.10) |
-0.04 (-0.14, 0.06) |
0.01 (-0.09, 0.12) |
0.01 (-0.09, 0.11) |
-0.12 (-0.23, -0.02) |
||||||
| Total GM vol |
0.70 (0.65, 0.75) |
0.19 (0.10, 0.29) |
-0.24 (-0.33, -0.14) |
0.67 (0.60, 0.72) |
0.00 (-0.10, 0.11) |
0.22 (0.12, 0.32) |
0.07 (-0.04, 0.17) |
|||||||
| Temporal vol |
0.18 (0.08, 0.27) |
-0.32 (-0.41, -0.23) |
0.46 (0.38, 0.54) |
0.01 (-0.10, 0.11) |
0.14 (0.03, 0.24) |
0.04 (-0.06, 0.15) |
||||||||
| Hippocamp. vol |
-0.21 (-0.30, -0.11) |
0.05 (-0.05, 0.15) |
0.06 (-0.06, 0.16) |
0.12 (0.02, 0.22) |
0.13 (0.03, 0.23) |
|||||||||
| Ventricle vol |
-0.15 (-0.25, -0.05) |
-0.06 (-0.17, 0.04) |
-0.15 (-0.25, -0.05) |
-0.09 (-0.19, 0.02) |
||||||||||
| Frontal lobe vol |
-0.06 (-0.16, 0.05) |
0.15 (0.04, 0.25) |
0.10 (-0.00, 0.20) |
|||||||||||
| Processing speed |
0.01 (-0.09, 0.11) |
0.07 (-0.04, 0.17) |
||||||||||||
| Executive function |
0.24 (0.13, 0.33) |
Note: Coefficients, unless stated otherwise, are Pearson correlation coefficients (with 95% confidence intervals using Fisher’s z-transformation) [53].a Denotes coefficients within the 24-hour time-use composition using pairwise symmetric balance coordinates (with non-parametric bootstrap 95% confidence intervals on 1000 bootstrap samples). LPA = light physical activity; MVPA = moderate-vigorous physical activity; SB = sedentary behaviour; vol = volume (ml); GM = grey matter; WMH = white matter hyperintensity. Correlations between sex (male = 0, female = 1) and other variables were explored using point biserial correlations, with positive correlations reflecting a positive relationship between female sex and the other variable. Bold denotes that p-value is statistically significant (p < 0.05)