Table 1 Descriptive statistics of the full sample and the within-pair sample I. Data presented for the dizygotic (DZ) and monozygotic (MZ) twins includes those individuals who were available for the within-pair analysis. Values are mean (standard deviation, SD) unless otherwise indicated
Full sample | Within-pair sample I | ||
|---|---|---|---|
N = 41,550 | DZ twin individuals N = 22,062 | MZ twin individuals N = 8110 | |
Age at baseline | 58.0 (10.1) | 56.7 (9.1) | 56.6 (9.1) |
Age range at baseline | 41–97 | 41–91 | 41–88 |
Women, N (%) | 22,193 (53.4) | 11,621 (52.7) | 4606 (56.8) |
BMI | 25.0 (3.5) | 25.0 (3.5) | 24.9 (3.5) |
Tobacco user, N (%) | 24,491 (58.9) | 13,282 (60.2) | 4549 (56.1) |
Years of education | 10.6 (3.2) | 10.7 (3.2) | 11.0 (3.2) |
§Physical activity, median (IQR) | |||
Born before 1926 | 1 (1) | 1 (1) | 1 (1) |
Born after 1926 | 3 (2) | 3 (2) | 3 (2) |
Living alone, N (%) | 9005 (21.7) | 4395 (19.9) | 1558 (19.2) |
FI, median (IQR) | 0.108 (0.108) | 0.102 (0.108) | 0.102 (0.108) |
Categorized FI | |||
Non-frail, N (%) | 15,464 (37.2) | 8557 (38.8) | 3133 (38.6) |
Pre-frail, N (%) | 22,354 (53.8) | 11,757 (53.3) | 4298 (53.0) |
Frail, N (%) | 3732 (9.0) | 1748 (7.9) | 679 (8.4) |
Dementia diagnosis during follow-up, N (%) | 3183 (7.7) | 1364 (6.2) | 494 (6.1) |
Time to diagnosis, median (IQR) | 16.0 (2.4) | 16.1 (2.3) | 16.1 (2.2) |
Died during follow-up, N (%) | 9932 (23.9) | 2012 (9.1) | 756 (9.3) |