Table 1.
Baseline characteristics of participants by incident dementia status
| Characteristics | No incident dementia (n = 57,008) | Incident dementia (n = 494) | Total (n = 57,502) |
|---|---|---|---|
| Age at accelerometry (years) | 62.37 ± 7.83 | 69.95 ± 5.05 | 62.42 ± 7.83 |
| Female (Yes/No) | 51,392 (56.67) | 246 (47.22) | 51,638 (56.62) |
| Non‐White ethnicity (Yes/No) | 2715 (2.99) | 14 (2.69) | 2729 (2.99) |
| Townsend deprivation index | −1.75 ± 2.81 | −1.85 ± 2.78 | −1.75 ± 2.81 |
| Recruitment regions (Yes/No) | |||
| England | 81,411 (89.78) | 486 (93.28) | 81,897 (89.8) |
| Wales | 3397 (3.75) | 9 (1.73) | 3406 (3.73) |
| Scotland | 5871 (6.47) | 26 (4.99) | 5897 (6.47) |
| Education level | |||
| Degree or above | 39,723 (43.81) | 205 (39.35) | 39,928 (43.78) |
| Any other qualification | 43,446 (47.91) | 224 (42.99) | 43,670 (47.88) |
| No qualification | 7510 (8.28) | 92 (17.66) | 7602 (8.34) |
| Season of accelerometer wear (Yes/No) | |||
| Spring | 20,524 (22.63) | 112 (21.5) | 20,636 (22.63) |
| Summer | 23,643 (26.07) | 153 (29.37) | 23,796 (26.09) |
| Autumn | 27,129 (29.92) | 150 (28.79) | 27,279 (29.91) |
| Winter | 19,383 (21.38) | 106 (20.35) | 19,489 (21.37) |
| Healthy diet score | 2.69 ± 1.17 | 2.86 ± 1.20 | 2.69 ± 1.17 |
| Smoking status | |||
| Never | 52,177 (57.54) | 244 (46.83) | 52,421 (57.48) |
| Previous | 32,833 (36.21) | 249 (47.79) | 33,082 (36.27) |
| Current | 5669 (6.25) | 28 (5.37) | 5697 (6.25) |
| Alcohol consumption | |||
| Not current | 5365 (5.92) | 57 (10.94) | 5422 (5.95) |
| Two or less times a week | 41,985 (46.3) | 203 (38.96) | 42,188 (46.26) |
| Three or more times a week | 43,329 (47.78) | 261 (50.1) | 43,590 (47.8) |
| Health status (Yes/No) | |||
| Obesity | 17,616 (19.43) | 113 (21.69) | 17,729 (19.44) |
| Diabetes history | 4319 (4.76) | 64 (12.28) | 4383 (4.81) |
| Hypertension history | 24,571 (27.1) | 219 (42.03) | 24,790 (27.18) |
| Cardiovascular diseases history | 22,143 (24.42) | 237 (45.49) | 22,380 (24.54) |
| Depression history | 8018 (8.84) | 49 (9.4) | 8067 (8.85) |
| APOE ε4 carrier (Yes/No) | 25,548 (28.17) | 229 (43.95) | 25,777 (28.26) |
| Circadian markers | |||
| L5 (counts/min) | 3.15 ± 1.18 | 3.27 ± 1.29 | 3.15 ± 1.18 |
| M10 (counts/min) | 47.42 ± 15.00 | 39.74 ± 13.80 | 47.37 ± 15.01 |
| RA (arbitrary units) | 0.87 ± 0.06 | 0.83 ± 0.08 | 0.87 ± 0.06 |
| L5 onset time (h) | 24.87 ± 1.09 | 24.75 ± 1.16 | 24.87 ± 1.09 |
| M10 onset time (h) | 8.53 ± 1.34 | 8.31 ± 1.16 | 8.53 ± 1.34 |
| Interdaily stability (arbitrary units) | 0.54 ± 0.13 | 0.58 ± 0.12 | 0.54 ± 0.13 |
| Intradaily variability (arbitrary units) | 0.91 ± 0.24 | 0.91 ± 0.22 | 0.91 ± 0.24 |
| Sleep duration (hours) | 7.28 ± 0.89 | 7.20 ± 1.04 | 7.28 ± 0.89 |
| Sleep efficiency (%) | 76.17 ± 7.24 | 75.02 ± 8.74 | 76.16 ± 7.25 |
| Total MVPA volume (minutes/week) | 156.61 ± 148.85 | 97.58 ± 115.38 | 156.27 ± 148.74 |
Note: Values are expressed as No. (%) for categorical variables and mean ± SD for continuous variables, unless specified otherwise. Includes imputed values for covariates.
Abbreviations: APOE, apolipoprotein E; L5, the least active 5‐h period; M10, the most active 10‐h period; RA, relative amplitude; MVPA, moderate to vigorous physical activity; PRS, polygenic risk score; SD, standard deviation.