Table 1.
Participant characteristics across categories of ST (n = 2,027)
| <6 h/day (n = 214) | 6 to <8 h/day (n = 722) | 8 to <10 h/day (n = 825) | ≥10 h/day (n = 266) | P for trend | |
|---|---|---|---|---|---|
| Age (years) | 44.6 ± 3.6 | 45.2 ± 3.7 | 45.5 ± 3.5 | 45.5 ± 3.3 | 0.002 |
| Sex | <0.001 | ||||
| Female, n (%) | 137 (64%) | 441 (61%) | 464 (56%) | 123 (46%) | |
| Male, n (%) | 77 (36%) | 281 (39%) | 361 (44%) | 143 (54%) | |
| Race | <0.001 | ||||
| Black, n (%) | 116 (54%) | 319 (44%) | 296 (36%) | 107 (40%) | |
| White, n (%) | 98 (46%) | 403 (56%) | 529 (64%) | 159 (60%) | |
| Education (years) | 14 ± 2 | 15 ± 2 | 16 ± 3 | 16 ± 3 | <0.001 |
| Total family income ($/year) | <0.001 | ||||
| <20,000 | 49 (23%) | 104 (14%) | 71 (9%) | 31 (12%) | |
| 20,000–49,999 | 26 (12%) | 50 (7%) | 50 (6%) | 18 (7%) | |
| 50,000–99,999 | 28 (13%) | 102 (14%) | 98 (12%) | 24 (9%) | |
| ≥100,000 | 111 (52%) | 466 (65%) | 606 (74%) | 193 (73%) | |
| BMI (kg/m2) | |||||
| Year 20 | 28.7 ± 6.3 | 29.2 ± 6.6 | 28.8 ± 7.6 | 29.1 ± 6.7 | 0.830 |
| Year 25* | 29.1 ± 6.3 | 29.0 ± 6.4 | 28.9 ± 7.9 | 29.0 ± 6.5 | 0.762 |
| Change (year 25 − year 20)* | 0.5 ± 2.5 | 0.5 ± 2.3 | 0.7 ± 2.5 | 0.5 ± 2.5 | 0.452 |
| Smoking | <0.001 | ||||
| Current, n (%) | 45 (21%) | 156 (22%) | 173 (21%) | 62 (23%) | |
| Former, n (%) | 63 (29%) | 124 (17%) | 112 (14%) | 33 (12%) | |
| Never, n (%) | 106 (50%) | 442 (61%) | 540 (66%) | 171 (64%) | |
| Alcohol consumption (drinks/day) | 0.314 | ||||
| 0 | 87 (42%) | 309 (44%) | 374 (46%) | 118 (45%) | |
| 0.1–1.9 | 72 (35%) | 248 (35%) | 290 (36%) | 99 (38%) | |
| ≥2.0 | 47 (22%) | 153 (21%) | 147 (18%) | 46 (17%) | |
| Hypertension (%) | |||||
| Year 20 | 52 (24%) | 191 (27%) | 194 (23%) | 70 (26%) | 0.555 |
| Year 25* | 61 (32%) | 198 (33%) | 204 (29%) | 74 (34%) | 0.322 |
| Change (year 25 − year 20)* | 21 (11%) | 57 (9%) | 69 (10%) | 24 (11%) | 0.862 |
| Total cholesterol (mg/dL) | |||||
| Year 20 | 183 ± 32 | 188 ± 35 | 186 ± 35 | 191 ± 34 | 0.080 |
| Year 25* | 192 ± 34 | 196 ± 37 | 194 ± 34 | 195 ± 34 | 0.850 |
| Change (year 25 − year 20)* | 10 ± 26 | 8 ± 31 | 7 ± 30 | 4 ± 33 | 0.050 |
| Accelerometer wear time (h/day) | 13.7 ± 1.6 | 14.3 ± 1.2 | 15.0 ± 1.1 | 16.3 ± 1.7 | <0.001 |
| MVPA, median min/day [IQR]† | 38 [23, 58] | 30 [17, 48] | 26 [16, 41] | 22 [14, 36] | <0.001 |
| Average cpm, median [IQR]† | 506 [421, 624] | 386 [319, 483] | 317 [252, 391] | 246 [206, 318] | <0.001 |
| %ST | 38 | 50 | 60 | 67 | <0.001 |
| Sedentary–to–light-activity ratio [IQR]† | 0.7 [0.6, 0.8] | 1.1 [0.9, 1.3] | 1.6 [1.4, 1.9] | 2.3 [1.9, 2.6] | <0.001 |
IQR, interquartile range. Boldface type denotes statistically significant differences across groups.
*n = 1,718 included in analysis of 5-year follow-up data;
†log transformed for analysis.