Table 1.
Descriptive Characteristics of the Study Population
| Moderate‐to‐vigorous physical activity, times/wk | |||||
|---|---|---|---|---|---|
| 0 | 1–2 | 3–4 | ≥5 | P value | |
| Follow‐up period, y, mean (SD) | 6.5 (1.5) | 6.7 (1.2) | 6.6 (1.3) | 6.6 (1.3) | 0.293 |
| Number of participants | 8460 | 3024 | 2738 | 4624 | |
| PM2.5 range, μg/m3 | 26.2 (3.1) | 26.2 (2.9) | 26.1 (3.1) | 26.1 (3.0) | 0.361 |
| PM10 range, μg/m3 | 51.5 (4.7) | 51.6 (4.6) | 51.4 (4.8) | 51.5 (4.7) | 0.809 |
| Age, y, mean (SD) | 60.6 (11.9) | 56.1 (11.5) | 57.9 (10.8) | 60.4 (10.5) | <0.001 |
| Sex, n (%) | |||||
| Male | 2808 (33.2) | 1194 (39.5) | 1080 (39.4) | 2100 (45.4) | <0.001 |
| Female | 5652 (66.8) | 1830 (60.5) | 1658 (60.6) | 2524 (54.6) | |
| Household income, quartile, n (%) | |||||
| First (highest) | 3438 (40.6) | 1360 (45.0) | 1264 (46.2) | 2135 (46.2) | <0.001 |
| Second | 1933 (22.9) | 671 (22.2) | 575 (21.0) | 990 (21.4) | |
| Third | 1334 (15.8) | 417 (13.8) | 401 (14.7) | 653 (14.1) | |
| Fourth (lowest) | 1755 (20.7) | 576 (19.1) | 498 (18.2) | 846 (18.3) | |
| Smoking, n (%) | |||||
| Never smoker | 6563 (77.6) | 2145 (70.9) | 1962 (71.7) | 3200 (69.2) | <0.001 |
| Past smoker | 1217 (14.4) | 581 (19.2) | 576 (21.0) | 1117 (24.2) | |
| Current smoker | 680 (8.0) | 298 (9.9) | 200 (7.3) | 307 (6.6) | |
| Alcohol intake, times/wk, n (%) | |||||
| 0 | 6649 (78.6) | 2008 (66.4) | 1886 (68.9) | 3162 (68.4) | <0.001 |
| 1–2 | 1175 (13.9) | 754 (24.9) | 632 (23.1) | 973 (21.0) | |
| 3–4 | 357 (4.2) | 182 (6.0) | 159 (5.8) | 305 (6.6) | |
| ≥5 | 279 (3.3) | 80 (2.7) | 61 (2.2) | 184 (4.0) | |
| Body mass index, kg/m2, mean (SD) | 23.5 (3.3) | 23.3 (3.1) | 23.4 (3.0) | 23.5 (2.9) | 0.004 |
| Systolic blood pressure, mm Hg, mean (SD) | 123.0 (15.9) | 121.3 (15.2) | 122.2 (15.3) | 124.1 (15.2) | <0.001 |
| Fasting serum glucose, mg/dL, mean (SD) | 100.1 (23.3) | 98.1 (19.7) | 99.1 (20.2) | 100.1 (22.0) | <0.001 |
| Total cholesterol, mg/dL, mean (SD) | 194.1 (40.1) | 193.3 (36.6) | 194.0 (36.8) | 191.8 (38.5) | 0.008 |
| Charlson comorbidity index, n (%) | |||||
| ≤1 | 2010 (23.8) | 707 (23.4) | 538 (19.7) | 965 (20.9) | <0.001 |
| 2 | 2540 (30.0) | 1016 (33.6) | 941 (34.4) | 1400 (30.3) | |
| ≥3 | 3910 (46.2) | 1301 (43.0) | 1259 (46.0) | 2259 (48.9) | |
P values calculated by chi‐squared test for categorical variables and ANOVA for continuous variables. PM2.5 indicates particulate matter with particles ≤2.5 µm; and PM10, particulate matter with particles <10 µm.