Table 2.
The mean scores and ANCOVA results of cognitive tests before and after intervention.
|
Mean (SD) |
Residuals comparison (ANCOVAa) | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Main effect of the group | Multiple comparisons by Dunnett's method | |||||||||||||||
| PCG | 3gIG | 6gIG | 3gIG vs. PCG | 6gIG vs. PCG | ||||||||||||
| Pre | Post | Residual (post-pre) | Pre | Post | Residual (post-pre) | Pre | Post | Residual (post-pre) | F-value | p-value | t-value | Adj. p-value | t-value | Adj. p-value | ||
| WMS-R | ||||||||||||||||
| Logical memory I (immediate) | Score (0–50) |
22.71 (6.34) |
26.74 (7.18) |
4.03 (5.15) |
23.89 (5.03) |
27.00 (4.64) |
3.11 (4.06) |
23.70 (6.13) |
27.70 (5.79) |
4.00 (4.56) |
0.68 | 0.51 | −0.72 | 0.70 | 0.45 | 0.86 |
| Logical memory II (delayed) | Score (0–50) |
17.23 (6.89) |
22.17 (7.2) |
4.94 (4.17) |
19.00 (6.75) |
23.40 (6.01) |
4.40 (4.63) |
19.21 (6.50) |
22.91 (7.38) |
3.70 (5.92) |
0.23 | 0.79 | −0.07 | 1.00 | −0.62 | 0.76 |
| Digit span forward |
Score (0–12) |
8.14 (2.10) |
7.91 (2.29) |
−0.23 (1.65) |
8.06 (2.04) |
7.97 (2.13) |
−0.09 (1.85) |
8.48 (2.44) |
7.88 (2.01) |
−0.61 (1.89) |
0.49 | 0.61 | 0.49 | 0.84 | −0.52 | 0.83 |
| Digit span backward |
Score (0–12) |
6.57 (1.96) |
6.46 (1.98) |
−0.11 (1.51) |
6.77 (1.68) |
6.49 (1.42) |
−0.29 (1.53) |
6.67 (1.69) |
6.70 (1.70) |
0.03 (1.51) |
0.52 | 0.59 | −0.31 | 0.93 | 0.70 | 0.71 |
| Total of digit span |
Score (0–24) |
14.71 (3.82) |
14.37 (3.75) |
−0.34 (2.61) |
14.83 (3.24) |
14.46 (3.17) |
−0.37 (2.73) |
15.15 (3.70) |
14.58 (3.27) |
−0.58 (2.61) |
0.01 | 0.99 | 0.15 | 0.98 | 0.03 | 1.00 |
| Visual memory span forward |
Score (0–14) |
9.63 (1.88) |
9.63 (1.66) |
0.00 (1.59) |
9.09 (1.52) |
9.26 (1.77) |
0.17 (1.84) |
9.30 (1.67) |
9.15 (1.77) |
−0.15 (1.92) |
0.26 | 0.77 | −0.20 | 0.97 | −0.71 | 0.70 |
| Visual memory span backward |
Score (0–12) |
8.57 (2.03) |
8.54 (1.77) |
−0.03 (1.99) |
7.94 (1.63) |
8.23 (1.26) |
0.29 (1.60) |
8.12 (1.62) |
7.91 (1.49) |
−0.21 (1.92) |
0.97 | 0.38 | −0.40 | 0.89 | −1.36 | 0.30 |
| Total of visual memory span |
Score (0–26) |
18.20 (3.31) |
18.17 (2.95) |
−0.03 (2.93) |
17.03 (2.61) |
17.49 (2.39) |
0.46 (2.50) |
17.42 (2.78) |
17.06 (2.62) |
−0.36 (2.76) |
0.85 | 0.43 | −0.21 | 0.97 | −1.22 | 0.37 |
| AVLT | ||||||||||||||||
| Immediate recall | Score (0–15) |
10.00 (3.43) |
10.37 (3.15) |
0.37 (3.38) |
9.46 (2.33) |
10.23 (2.87) |
0.77 (2.82) |
9.55 (3.15) |
10.15 (2.53) |
0.61 (2.36) |
0.01 | 0.99 | 0.03 | 1.00 | −0.10 | 0.99 |
| Delayed recall | Score (0–15) |
9.46 (3.51) |
10.40 (3.42) |
0.94 (3.18) |
9.40 (2.57) |
10.29 (1.93) |
0.89 (2.25) |
9.58 (2.94) |
10.27 (2.76) |
0.70 (2.35) |
0.12 | 0.89 | −0.33 | 0.92 | −0.47 | 0.85 |
| Trail making test | ||||||||||||||||
| Part A | Seconds to completion | 41.80 (12.81) |
38.17 (12.35) |
−3.63 (10.70) |
38.80 (13.48) |
34.43 (13.5) |
−4.37 (12.05) |
39.42 (13.29) |
36.03 (14.95) |
−3.39 (14.27) |
0.48 | 0.62 | −0.98 | 0.52 | −0.43 | 0.87 |
| Part B | Seconds to completion | 86.03 (25.72) |
83.12 (33.24) |
−2.44 (25.77) |
84.51 (25.21) |
84.35 (36.08) |
−0.44 (23.49) |
92.85 (44.58) |
75.85 (23.72) |
−17.00 (33.20) |
4.05 | 0.02* | 0.28 | 0.94 | −2.34 | 0.04* |
| Word fluency | ||||||||||||||||
| Letter, “Ka” | Number of words | 11.77 (4.45) |
13.31 (4.23) |
1.54 (3.68) |
13.40 (2.96) |
13.11 (3.66) |
−0.29 (3.82) |
13.24 (3.61) |
14.55 (4.31) |
1.30 (4.08) |
2.52 | 0.09 | −1.39 | 0.28 | 0.83 | 0.62 |
| Letter, “Ho” | Number of words | 9.09 (3.93) |
9.43 (3.54) |
0.34 (3.32) |
9.34 (3.37) |
9.51 (3.04) |
0.17 (3.20) |
9.88 (3.99) |
10.33 (3.84) |
0.45 (2.76) |
0.46 | 0.63 | −0.09 | 0.99 | 0.79 | 0.65 |
| Animals | Number of words | 17.69 (4.96) |
18.11 (4.89) |
0.43 (3.48) |
18.63 (3.44) |
17.46 (4.01) |
−1.17 (3.54) |
18.55 (3.83) |
19.27 (5.09) |
0.73 (4.31) |
2.81 | 0.07 | −1.57 | 0.21 | 0.78 | 0.66 |
| Vegetables | Number of words | 14.32 (4.23) |
15.31 (4.41) |
0.85 (2.58) |
15.20 (3.39) |
15.46 (3.90) |
0.26 (3.70) |
15.82 (4.42) |
16.30 (4.46) |
0.48 (2.81) |
0.16 | 0.85 | −0.48 | 0.84 | 0.02 | 1.00 |
| WAIS-III | ||||||||||||||||
| Similarities | Score (0–33) |
22.77 (4.49) |
23.26 (4.70) |
0.49 (2.58) |
22.03 (4.60) |
23.80 (3.26) |
1.77 (3.68) |
22.42 (4.06) |
22.94 (3.72) |
0.52 (3.29) |
1.15 | 0.32 | 1.32 | 0.32 | −0.01 | 1.00 |
a
Covariates: sex, age, blood pressure, BMI, education and value of pre-test. PCG, Placebo control group; 3gIG, Intervention group who takes amino acid 3 g per day; 6gIG, Intervention group who takes amino acid 6 g per day; WMS-R, Wechsler memory scale revised; WAIS-III, Wechsler Adult Intelligence Scale-III; ANCOVA, analysis of covariance; AVLT, auditory verbal learning test; BMI: body mass index;
*
p < 0.05.