TABLE 3.
Adjusted change in muscle power and strength and physical performance over 12 mo by intervention group and the difference in 12-mo change between intervention groups1
| Vitamin D |
Placebo |
Difference in change (vitamin D – placebo) |
P value for difference in change by group | |||
|---|---|---|---|---|---|---|
| N2 | LS Means ± SE | N2 | LS Means ± SE | LS Means ± SE | ||
| Muscle power and strength | ||||||
| Leg power, watts | 61 | –11.96 ± 3.75 | 61 | –7.97 ± 3.77 | –4.00 ± 5.26 | 0.45 |
| Leg power quality, watts/kg | 61 | –0.13 ± 0.04 | 61 | –0.10 ± 0.04 | –0.03 ± 0.06 | 0.63 |
| Knee extensor strength, Nm | 45 | –8.09 ± 1.75 | 50 | –3.84 ± 1.66 | –4.25 ± 2.37 | 0.08 |
| Knee extensor quality, Nm/kg | 45 | –0.09 ± 0.02 | 50 | –0.04 ± 0.02 | –0.04 ± 0.03 | 0.15 |
| Grip strength, kg | 56 | –1.54 ± 0.50 | 64 | –1.39 ± 0.48 | –0.15 ± 0.69 | 0.82 |
| Physical performance | ||||||
| SPPB score (0–12) | 60 | 1.64 ± 0.22 | 63 | 1.83 ± 0.22 | –0.18 ± 0.29 | 0.53 |
| Health ABC PPB score (0–4) | 54 | 0.19 ± 0.04 | 51 | 0.17 ± 0.04 | 0.02 ± 0.06 | 0.75 |
| Balance time, s | 59 | 1.32 ± 1.98 | 57 | 3.06 ± 2.02 | –1.74 ± 2.58 | 0.50 |
| 4-meter usual gait speed, meters/s | 60 | 0.07 ± 0.02 | 61 | 0.08 ± 0.02 | 0.00 ± 0.02 | 0.83 |
| Chair stand times, s | 56 | –3.12 ± 0.53 | 54 | –3.04 ± 0.53 | –0.08 ± 0.59 | 0.89 |
| Timed Up and Go, s | 58 | 1.01 ± 0.21 | 59 | 0.98 ± 0.21 | 0.03 ± 0.27 | 0.92 |
| 4 stair climb, s | 60 | 0.41 ± 0.07 | 61 | 0.32 ± 0.07 | 0.09 ± 0.10 | 0.35 |
| Force plate: firm base | ||||||
| 95% confidence ellipse path, cm2 | 54 | 0.03 ± 0.04 | 51 | 0.00 ± 0.04 | 0.03 ± 0.06 | 0.61 |
| Average sway velocity, cm/s | 54 | 0.01 ± 0.01 | 51 | 0.01 ± 0.01 | 0.00 ± 0.02 | 0.94 |
| ML maximum displacement, cm | 54 | 0.06 ± 0.04 | 51 | –0.01 ± 0.04 | 0.07 ± 0.05 | 0.21 |
| AP maximum displacement, cm | 54 | 0.02 ± 0.03 | 51 | 0.00 ± 0.03 | 0.02 ± 0.04 | 0.59 |
| Force plate: foam base | ||||||
| 95% confidence ellipse path, cm2 | 53 | –0.16 ± 0.09 | 55 | –0.05 ± 0.09 | –0.11 ± 0.13 | 0.39 |
| Average sway velocity, cm/sec | 53 | 0.04 ± 0.03 | 55 | 0.00 ± 0.03 | 0.04 ± 0.04 | 0.37 |
| ML maximum displacement, cm | 53 | –0.04 ± 0.05 | 55 | –0.06 ± 0.05 | 0.01 ± 0.07 | 0.86 |
| AP maximum displacement, cm | 53 | –0.02 ± 0.05 | 55 | –0.07 ± 0.04 | 0.04 ± 0.06 | 0.49 |
| GAITRite: usual pace | ||||||
| Double support, % of cycle | 54 | 0.03 ± 0.27 | 58 | 0.33 ± 0.26 | –0.30 ± 0.37 | 0.41 |
| Single support, % of cycle | 54 | 0.00 ± 0.14 | 58 | –0.11 ± 0.13 | 0.11 ± 0.19 | 0.56 |
| Stance, % of cycle | 54 | 0.00 ± 0.14 | 58 | 0.11 ± 0.13 | –0.11 ± 0.19 | 0.58 |
| Stride length, cm | 54 | –0.53 ± 1.00 | 58 | –1.02 ± 0.98 | 0.49 ± 1.38 | 0.72 |
| Stride width, cm | 54 | 0.57 ± 0.21 | 58 | 0.13 ± 0.21 | 0.45 ± 0.29 | 0.13 |
| Swing, % of cycle | 54 | 0.01 ± 0.14 | 58 | –0.10 ± 0.13 | 0.11 ± 0.19 | 0.57 |
| Velocity, cm/s | 54 | 0.42 ± 1.49 | 58 | –0.07 ± 1.45 | 0.49 ± 2.05 | 0.81 |
| GAITRite: fast pace | ||||||
| Double support, % of cycle | 55 | 1.06 ± 0.33 | 60 | 0.73 ± 0.32 | 0.33 ± 0.45 | 0.46 |
| Single support, % of cycle | 55 | –0.50 ± 0.17 | 60 | –0.33 ± 0.16 | –0.16 ± 0.23 | 0.48 |
| Stance, % of cycle | 55 | 0.50 ± 0.17 | 60 | 0.33 ± 0.16 | 0.18 ± 0.23 | 0.44 |
| Stride length, cm | 55 | –4.21 ± 1.12 | 60 | –4.49 ± 1.09 | 0.28 ± 1.53 | 0.85 |
| Stride width, cm | 55 | 0.00 ± 0.20 | 60 | 0.14 ± 0.20 | –0.15 ± 0.28 | 0.60 |
| Swing, % of cycle | 55 | –0.49 ± 0.17 | 60 | –0.33 ± 0.16 | –0.16 ± 0.23 | 0.48 |
| Velocity, cm/s | 55 | –11.03 ± 2.13 | 60 | –6.65 ± 2.06 | –4.37 ± 2.88 | 0.13 |
AP, anterior-posterior; Health ABC PPB, Health ABC Physical Performance Battery; LS means, least squares means; ML, medial-lateral; SE, standard error; SPPB, Short Physical Performance Battery.
1
LS means ± SE adjusted for age, sex, race, and season (time-varying).
2
Number of participants with measures at 12-mo visit.