Table 2.
Between-genotype comparisons of demographic data in the sample of older adults (age range = 60–70 years).
| Genotype | Older participants (n = 154) | |||||
|---|---|---|---|---|---|---|
| COMT | Val/Val | Val/Met | Met/Met | |||
| BDNF | Any Met | Val/Val | Any Met | Val/Val | Any Met | Val/Val |
| Demographics | ||||||
| n | 9 | 26 | 18 | 60 | 17 | 24 |
| Age (SD) | 65.7 (3.8) | 64.9 (3.3) | 64.3 (2.8) | 64.4 (2.6) | 62.8 (2.3) | 65.6 (2.6)a |
| Women/Men | 2/7 | 10/16 | 6/12 | 32/28 | 6/11 | 9/15b,c |
| Years of education (SD) | 10.8 (1.9) | 11.5 (1.7) | 10.6 (1.7) | 11.1 (1.8) | 11.1 (2.0) | 10.9 (1.5)a |
| State of health (SD) | 3.9 (0.6) | 3.8 (0.6) | 4.1 (0.6) | 4.0 (0.6) | 3.6 (0.7) | 3.8 (0.6)d |
| M.M.S.E. (SD) | 29.4 (0.7) | 29.4 (0.7) | 29.5 (0.6) | 29.4 (0.7) | 29.5 (0.9) | 29.3 (0.7)a |
State of health is based on four self-ratings on 5-point scales (1 = poor; 5 = excellent).
aTwo-way analyses of variance = n.s., except for a significant COMT × BDNF interaction for age, F(2,148) = 3.83, p < 0.05, η2 = 0.05. The pattern and statistical significance of the results reported in the article remain unchanged when individual differences in age within age groups are added as a covariate.
bχ2COMT = n.s.
cχ2BDNF = n.s.
dTwo-way analysis of variance = n.s., except for a significant effect of COMT on state of health, F(2,148) = 3.08, p < 0.05, η2 = 0.04.