Table 2.
Estimated marginal means (standard error) and p-values for pairwise comparisons of moderate-to-vigorous physical activity in min/day, as a function of DRD1 genotype, in the total sample and stratified by age
| Total sample | 66 years | 81–87 years | ||||
|---|---|---|---|---|---|---|
| DRD1 genotype | Model 1 | Model 2 | Model 1 | Model 2 | Model 1 | Model 2 |
| TT (lower efficacy) | 32.7 (26.6, 38.7) | 30.5 (23.3, 37.7) | 38.8 (34.7, 42.9) | 36.6 (28.4, 44.9) | 14.8 (10.1, 19.6) | 15.2 (8.2, 22.1) |
| CT (intermediate efficacy) | 37.7 (31.6, 43.8) | 32.7 (27.9, 37.5) | 39.8 (36.1, 43.5) | 32.1 (24.1, 40.2) | 23.1 (18.9, 27.3) | 24.5 (17.7, 31.3) |
| CC (higher efficacy) | 39.8 (32.4, 47.2) | 49.9 (40.8, 59.0) | 40.8 (33.9, 47.8) | 52.1 (40.3, 63.8) | 27.2 (19.5, 34.9) | 35.8 (26.8, 44.8) |
| TT vs. CC (p-value) | 0.043 | 0.001 | 0.626 | 0.036 | 0.007 | 0.000 |
| TT vs. CT (p-value) | 0.041 | 0.618 | 0.727 | 0.442 | 0.012 | 0.064 |
| CT vs. CC (p-value) | 0.538 | 0.001 | 0.798 | 0.007 | 0.354 | 0.049 |
DRD1 = dopamine D1 receptor polymorphism
Model 1 was adjusted for age, sex and physical function (5 STS and OLS) and included cohort as a factor in the total sample. Main effects of the two other SNPs are not included in Model 1. In Model 2, additional adjustments were made for main (i.e., DRD1, DRD2, DRD3) and interactive effects between the other SNPs (i.e., DRD1 x DRD2, DRD1 x DRD3, DRD2 x DRD3, and DRD1 x DRD2 x DRD3)