Table 1.
Characteristics of the young and older monozygotic and dizygotic individual twins participating into the current study
| Young 20–25 years | MZ vs DZ difference | Older 55–70 years | MZ vs DZ difference | |||
|---|---|---|---|---|---|---|
| MZ | DZ | p value | MZ | DZ | p value | |
| Chronological age (years) | 22.7 (0.9) | 22.4 (0.7) | 0.005 | 61.4 (3.7) | 62.1 (3.8) | 0.29 |
| DNAm age (predicted years) | 22.2 (3.8) | 21.3 (3.6) | 0.015 | 61.2 (5.7) | 62.6 (5.4) | 0.096 |
| Age acceleration (residuals) | 0.29 (3.54) | − 0.40 (3.48) | 0.065 | − 0.02 (5.46) | 0.65 (4.95) | 0.35 |
| Body mass index (kg/m2) | 23.0 (3.5) | 23.7 (4.3) | 0.055 | 27.2 (5.0) | 28.2 (4.7) | 0.11 |
| Women, n (%) | 218 (65%) | 142 (59%) | 0.28 | 162 (66%) | 44 (52%) | 0.11 |
| Never smokers, n (%) | 177 (53%) | 126 (52%) | 0.001 | 117 (48%) | 42 (50%) | 0.95 |
| Former smokers, n (%) | 30 (9%) | 17 (7%) | – | 86 (35%) | 29 (35%) | – |
| Current smokers, n (%) | 101 (30%) | 98 (40%) | – | 41 (17%) | 13 (15%) | – |
Values are means and standard deviations unless otherwise stated. MZ, monozygotic; DZ dizygotic. Differences between groups on continuous variables were tested on design corrected T-test for independent samples and chi-square test (sex, smoking)