TABLE 2.
Summary of characteristics of study participants (n = 198).
| All (n = 198) | TPA | LTPA | OPA | ||||||||
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| Low (n = 99) | High (n = 99) | P-value | Low (n = 99) | High (n = 99) | P-value | Low (n = 99) | High (n = 99) | P-value | |||
| Age, years | mean (SD) | 54.38 (16.42) | 56.38 (15.71) | 52.38 (16.95) | 0.104 | 56.1 (15.49) | 52.67 (17.20) | 0.224 | 55.52 (16.88) | 53.25 (15.95) | 0.211 |
| median (min, max) | 61 (20, 80) | 63 (22, 80) | 57 (20, 77) | 62 (22, 80) | 58 (20, 79) | 63 (22, 79) | 57 (20, 80) | ||||
| Follow up interval, years | mean (SD) | 4.87 (0.64) | 4.90 (0.63) | 4.85 (0.66) | 0.499 | 4.95 (0.63) | 4.80 (0.65) | 0.066 | 4.88 (0.63) | 4.87 (0.66) | 0.822 |
| median (min, max) | 5 (4, 7) | 5 (4, 7) | 5 (4, 7) | 5 (4, 7) | 5 (4, 7) | 5 (4, 7) | 5 (4, 7) | ||||
| Sex | |||||||||||
| Male, n (%) | 90 (45.45) | 45 (45.45) | 45 (45.45) | 1.000 | 44 (44.44) | 46 (46.46) | 0.775 | 36 (36.36) | 54 (54.55) | 0.010** | |
| Female, n (%) | 108 (54.55) | 54 (54.55) | 54 (54.55) | 55 (55.56) | 53 (53.54) | 63 (63.64) | 45 (45.45) | ||||
| Education,d years | mean (SD) | 16.34 (2.42) | 16.30 (2.43) | 16.38 (2.41) | 0.815 | 15.94 (2.28) | 16.75 (2.49) | 0.018* | 16.70 (2.62) | 15.99 (2.15) | 0.039* |
| median (min, max) | 16 (11, 24) | 16 (11, 22) | 16 (12, 24) | 16 (11, 22) | 16 (12, 24) | 16 (11, 24) | 16 (12, 22) | ||||
| NARTIQ | mean (SD) | 118.29 (8.05) | 118.12 (9.13) | 118.47 (6.84) | 0.399 | 117.35 (8.49) | 119.24 (7.51) | 0.158 | 118.06 (8.83) | 118.53 (7.22) | 0.617 |
| median (min, max) | 120.48 (94.16, 130.88) | 121.76 (94.16, 129.12) | 119.36 (98.00, 130.88) | 119.60 (94.16, 129.12) | 121.36 (98.00, 130.88) | 121.36 (99.36, 129.12) | 119.84 (94.16, 130.88) | ||||
| Race/ethnicity | |||||||||||
| Non-Hispanic White, n (%) | 119 (60.10) | 56 (56.57) | 63 (63.64) | 0.523 | 54 (54.55) | 65 (65.66) | 0.263 | 57 (57.58) | 62 (62.63) | 0.515 | |
| Non-Hispanic Black, n (%) | 46 (23.23) | 25 (25.25) | 21 (21.21) | 28 (28.28) | 18 (18.18) | 22 (22.22) | 24 (24.24) | ||||
| Others,a n (%) | 10 (5.05) | 4 (4.04) | 6 (6.06) | 4 (4.04) | 6 (6.06) | 7 (7.07) | 3 (3.03) | ||||
| Hispanic, n (%) | 23 (11.62) | 14 (14.14) | 9 (9.09) | 13 (13.13) | 10 (10.10) | 13 (13.13) | 10 (10.10) | ||||
| WMH (baseline), mm3 | mean (SD) | 1310.95 (3154.88) | 1313.23 (2839.32) | 1308.67 (3456.35) | 0.673 | 1586.33 (3979.69) | 1035.57 (2004.23) | 0.678 | 1118.76 (1954.73) | 1503.14 (4014.04) | 0.853 |
| median (min, max) | 79.5 (0, 22039) | 80 (0, 22039) | 79 (0, 20192) | 117 (0, 22039) | 62 (0, 8667) | 80 (0, 8593) | 79 (0, 22039) | ||||
| Cardiovascular risk indexc | mean (SD) | 0.27 (0.53) | 0.28 (0.52) | 0.25 (0.54) | 0.454 | 0.32 (0.55) | 0.22 (0.51) | 0.143 | 0.29 (0.52) | 0.24 (0.54) | 0.276 |
| median (min, max) | 0 (0, 2) | 0 (0, 2) | 0 (0, 2) | 0 (0, 2) | 0 (0, 2) | 0 (0, 2) | 0 (0, 2) | ||||
| Total Brain Volumec,d (baseline), cm3 | mean (SD) | 1005.18 (98.51) | 994.52 (110.21) | 1015.95 (84.28) | 0.127 | 985.92 (111.87) | 1024.24 (79.26) | 0.006** | 995.33 (103.05) | 1015.13 (93.16) | 0.159 |
| median (min, max) | 1011.94 (675.66, 1254.86) | 1011.39 (675.66, 1254.86) | 1014.26 (805.03, 1183.96) | 1000.16 (675.66, 1243.99) | 1021.98 (821.57, 1254.86) | 1004.30 (675.66, 1254.86) | 1019.87 (803.42, 1183.96) | ||||
| Mean cortical thicknessc,d (baseline), mm | mean (SD) | 2.54 (0.12) | 2.53 (0.11) | 2.54 (0.13) | 0.401 | 2.54 (0.11) | 2.53 (0.13) | 0.773 | 2.54 (0.11) | 2.53 (0.12) | 0.607 |
| median (min, max) | 2.53 (2.21, 2.82) | 2.52 (2.21, 2.79) | 2.55 (2.22, 2.82) | 2.53 (2.26, 2.79) | 2.54 (2.21, 2.82) | 2.53 (2.21, 2.82) | 2.52 (2.22, 2.80) | ||||
| Baseline cognition | |||||||||||
| Global cognitiond | mean (SD) | 0 (0.56) | –0.04 (0.57) | 0.04 (0.55) | 0.282 | –0.11 (0.52) | 0.11 (0.59) | 0.004** | –0.01 (0.6) | 0.01 (0.53) | 0.787 |
| median (min, max) | –0.03 (–1.38, 1.32) | –0.04 (–1.38, 1.19) | 0.05 (–1.36, 1.32) | –0.13 (–1.38, 1.19) | 0.07 (–1.36, 1.32) | –0.03 (–1.38, 1.26) | –0.03 (–1.38, 1.32) | ||||
| Fluid reasoning | mean (SD) | 0 (0.71) | –0.04 (0.68) | 0.04 (0.74) | 0.456 | –0.14 (0.68) | 0.14 (0.72) | 0.006** | 0.03 (0.70) | –0.04 (0.72) | 0.449 |
| median (min, max) | –0.01 (–1.63, 1.37) | –0.05 (–1.63, 1.34) | 0.07 (–1.51, 1.37) | –0.14 (–1.63, 1.33) | 0.15 (–1.51, 1.37) | 0 (–1.63, 1.37) | –0.02 (–1.62, 1.33) | ||||
| Processing speedd | mean (SD) | –0.02 (0.69) | –0.10 (0.66) | 0.05 (0.70) | 0.121 | –0.14 (0.63) | 0.10 (0.72) | 0.013* | –0.03 (0.72) | –0.01 (0.65) | 0.865 |
| median (min, max) | –0.05 (–1.67, 2.12) | –0.11 (–1.67, 1.66) | 0.07 (–1.46, 2.12) | –0.14 (–1.67, 1.66) | 0.11 (–1.46, 2.12) | –0.11 (–1.46, 2.12) | 0.07 (–1.67, 1.79) | ||||
| Memoryd | mean (SD) | –0.02 (0.84) | –0.03 (0.88) | –0.01 (0.80) | 0.875 | –0.12 (0.84) | 0.08 (0.83) | 0.102 | –0.04 (0.87) | 0 (0.80) | 0.771 |
| median (min, max) | 0.01 (–2.21, 1.61) | 0.01 (–2.15, 1.54) | –0.01 (–2.21, 1.61) | –0.13 (–2.15, 1.54) | 0.13 (–2.21, 1.61) | 0.01 (–2.15, 1.46) | –0.01 (–2.21, 1.61) | ||||
| Vocabulary | mean (SD) | 0.04 (0.77) | –0.01 (0.86) | 0.09 (0.67) | 0.929 | –0.06 (0.81) | 0.13 (0.72) | 0.093 | –0.02 (0.87) | 0.09 (0.66) | 0.978 |
| median (min, max) | 0.29 (–2.31, 1.04) | 0.35 (–2.31, 1.04) | 0.25 (–1.77, 0.98) | 0.17 (–2.31, 1.04) | 0.32 (–1.77, 0.98) | 0.34 (–2.31, 1.04) | 0.25 (–2.03, 0.98) | ||||
| Change of cognition | |||||||||||
| Global cognition | mean (SD) | –0.1 (0.26) | –0.13 (0.28) | –0.07 (0.23) | 0.058 | –0.14 (0.28) | –0.06 (0.23) | 0.114 | –0.10 (0.27) | –0.10 (0.25) | 0.857 |
| median (min, max) | –0.08 (–1.57, 0.45) *** b | –0.12 (–1.57, 0.45) | –0.03 (–0.78, 0.44) | –0.1 (–1.57, 0.34) | –0.06 (–0.69, 0.45) | –0.08 (–1.57, 0.45) | –0.08 (–0.78, 0.44) | ||||
| Fluid reasoning | mean (SD) | –0.15 (0.14) | –0.17 (0.16) | –0.13 (0.12) | 0.030* | –0.18 (0.15) | –0.13 (0.14) | 0.015* | –0.16 (0.16) | –0.15 (0.13) | 0.808 |
| median (min, max) | –0.14 (–1.15, 0.34) *** b | –0.17 (–1.15, 0.34) | –0.13 (–0.57, 0.19) | –0.16 (–1.15, 0.13) | –0.13 (–0.57, 0.34) | –0.14 (–1.15, 0.34) | –0.14 (–0.57, 0.19) | ||||
| Processing speed | mean (SD) | –0.18 (0.19) | –0.20 (0.20) | –0.16 (0.17) | 0.064 | –0.21 (0.19) | –0.15 (0.19) | 0.025* | –0.17 (0.20) | –0.19 (0.18) | 0.602 |
| median (min, max) | –0.17 (–1.22, 0.48) *** b | –0.20 (–1.22, 0.46) | –0.15 (–0.62, 0.48) | –0.2 (–1.22, 0.23) | –0.16 (–0.62, 0.48) | –0.17 (–1.22, 0.46) | –0.17 (–0.62, 0.48) | ||||
| Memory | mean (SD) | –0.13 (0.69) | –0.20 (0.73) | –0.05 (0.64) | 0.176 | –0.20 (0.75) | –0.05 (0.63) | 0.327 | –0.10 (0.70) | –0.15 (0.69) | 0.667 |
| median (min, max) | –0.07 (–2.54, 1.41) * b | –0.12 (–2.54, 1.41) | 0.04 (–1.88, 1.40) | –0.10 (–2.54, 1.20) | 0.02 (–1.52, 1.41) | –0.10 (–2.54, 1.41) | –0.03 (–1.88, 1.40) | ||||
| Vocabulary | mean (SD) | 0.06 (0.19) | 0.04 (0.21) | 0.08 (0.15) | 0.020* | 0.04 (0.21) | 0.08 (0.15) | 0.213 | 0.04 (0.21) | 0.08 (0.16) | 0.153 |
| median (min, max) | 0.06 (–1.37, 0.62) *** b | 0.02 (–1.37, 0.59) | 0.09 (–0.47, 0.62) | 0.04 (–1.37, 0.59) | 0.07 (–0.47, 0.62) | 0.04 (–1.37, 0.54) | 0.07 (–0.47, 0.62) | ||||
*p < 0.05; **p < 0.01; ***p < 0.001.
SD, standard deviation; TPA, total physical activity; LTPA, leisure time physical activity; OPA, occupational physical activity; WMH, white matter hyperintensity.
aOthers included Asian, others, and mixed race/ethnicity.
bOne sample Wilcoxon test (compared to 0) was used to determine if the cognition was significantly changed over 5 years.
cCardiovascular risk index has seven missing values; total brain volume has one missing value; mean cortical thickness has 12 missing values.
dThose variables were normally distributed continuous variables; p-values were obtained from t-test. The other continuous variables were not normally distributed; p-values were obtained from Wilcoxon test.
The dichotomous PA groups were split by median PA. The two levels of LTPA were high (≥1260 MET-min/week) and low (0 to <1260 MET-min/week). People included in the high LTPA group should perform at least 2.33 h of vigorous activities, 4.2 h of moderate activities, or 7 h of light activities per week. In terms of OPA, the people in high OPA group mainly work on jobs with high demands of outdoor and physical activities, such as construction workers, firefighters, police, truck drivers, real estate sales agents, etc. Bold values indicate significant values (p < 0.05 or 0.1).