Table 1.
Characteristics of participants and air pollution exposure (2002–2015).
| Osteoporosis-Related Fracture | |||
|---|---|---|---|
| Total Participants (n = 56,498) |
No Event (n = 51,100) |
Event (n = 5398) |
|
| Entry year | |||
| Sex (n, %) | |||
| Men | 26,243 (46.5) | 25,041 (49.0) | 1202 (22.3) * |
| Women | 30,224 (53.5) | 26,030 (51.0) | 4194 (77.7) |
| Age in the entry year (n, %) | |||
| 50–59 y | 20,673 (36.6) | 19,301 (37.8) | 1372 (25.4) * |
| 60–64 y | 15,183 (26.9) | 13,929 (27.3) | 1254 (23.2) |
| 65–69 y | 11,510 (20.4) | 10,235 (20.0) | 1275 (23.6) |
| 70–74 y | 5851 (10.4) | 5001 (9.8) | 850 (15.8) |
| 75–79 y | 2449 (4.3) | 1987 (3.9) | 462 (8.6) |
| 80–84 y | 720 (1.3) | 551 (1.1) | 169 (3.1) |
| 85+ y | 81 (0.1) | 67 (0.1) | 14 (0.3) |
| During follow-up | |||
| Charlson Comorbidity Index in the first year of follow-up (mean ± SD) | 0.36 ± 0.82 | 0.35 ± 0.82 | 0.44 ± 0.86 * |
| BMI (mean ± SD) | 24.2 ± 3.1 | 24.2 ± 3.0 | 24.1 ± 3.2 * |
| Smoking status (n, %) | |||
| Never-smoker | 39,255 (69.8) | 34,818 (68.4) | 4437 (82.8) * |
| Former smoker | 9593 (17.1) | 9145 (18.0) | 448 (8.4) |
| Current smoker | 7399 (13.2) | 6925 (13.6) | 474 (8.8) |
| Frequency of exercise per week (n, %) | |||
| 0 time | 9488 (16.9) | 8272 (16.3) | 1216 (22.7) * |
| 1–2 times | 4146 (7.4) | 3718 (7.3) | 428 (8.0) |
| 3–4 times | 2331 (4.1) | 2109 (4.1) | 222 (4.1) |
| 5–6 times | 736 (1.3) | 650 (1.3) | 86 (1.6) |
| 7 times or more | 39,551 (70.3) | 36,140 (71.0) | 3411 (63.6) |
| High alcohol intake | |||
| Yes | 2106 (4.2) | 1965 (4.4) | 141 (3.0) * |
| No | 47,560 (95.8) | 43,071 (95.6) | 4489 (97.0) |
| Income-based insurance fee in the entry year (n, %) | |||
| 0–19th percentiles | 4644 (8.4) | 4150 (8.3) | 494 (9.4) * |
| 20–39th percentiles | 7454 (13.5) | 6751 (13.5) | 703 (13.4) |
| 40–59th percentiles | 9175 (16.6) | 8292 (16.6) | 883 (16.8) |
| 60–79th percentiles | 9923 (18.0) | 8925 (17.9) | 998 (19.0) |
| 80–100th percentiles | 24,003 (43.5) | 21,826 (43.7) | 2177 (41.4) |
| Follow-up years (mean, SD) | 9.5 (3.0) | 9.8 (2.8) | 6.4 (3.1) * |
| Diagnosis of rheumatoid arthritis during follow-up (n, %) | |||
| Yes | 5913 (10.5) | 5251 (10.3) | 662 (12.3) * |
| No | 50,554 (89.5) | 45,820 (89.7) | 4734 (87.7) |
| Diagnosis of secondary causes of osteoporosis during follow-up (n, %) | |||
| Yes | 7733 (13.7) | 6997 (13.7) | 736 (13.6) |
| No | 48,732 (86.3) | 44,074 (86.3) | 4660 (86.4) |
| Exposure to oral glucocorticoids during follow-up (n, %) | |||
| Yes | 9197 (16.3) | 8432 (16.5) | 765 (14.2) * |
| No | 47,270 (83.7) | 42,639 (83.5) | 4631 (85.8) |
| Air pollution exposure in the last 3 years before the index year (mean ± SD) | |||
| PM10 (μg/m3) | 48.7 ± 7.3 | 48.2 ± 7.0 | 53.6 ± 7.9 * |
| SO2 (ppb) | 5.67 ± 1.37 | 5.66 ± 1.36 | 5.80 ± 1.47 * |
| CO (ppm) | 0.553 ± 0.119 | 0.549 ± 0.118 | 0.592 ± 0.121 * |
| NO2 (ppb) | 30.3 ± 8.2 | 30.3 ± 8.2 | 30.9 ± 7.9 * |
| O3 (ppb) | 22.3 ± 4.5 | 22.5 ± 4.4 | 20.4 ± 4.1 * |
| Air pollution exposure in the last 3 years before the index year (n, %) | |||
| PM10, Q1 (31.1–44.3 μg/m3) | 14,882 (26.4) | 14,298 (28.0) | 584 (10.8) * |
| PM10, Q2 (44.4–47.3 μg/m3) | 14,076 (24.9) | 13,385 (26.2) | 691 (12.8) |
| PM10, Q3 (47.4–51.2 μg/m3) | 13,752 (24.4) | 12,755 (25.0) | 997 (18.5) |
| PM10, Q4 (51.3–82.0 μg/m3) | 13,757 (24.4) | 10,633 (20.8) | 3124 (57.9) |
| SO2, Q1 (2.7–4.8 ppb) | 14,130 (25.0) | 12,566 (24.6) | 1564 (29.0) * |
| SO2, Q2 (4.9–5.3 ppb) | 14,777 (26.2) | 13,868 (27.2) | 909 (16.8) |
| SO2, Q3 (5.4–6.3 ppb) | 13,870 (24.6) | 12,423 (24.3) | 1447 (26.8) |
| SO2, Q4 (6.4–13.1 ppb) | 13,690 (24.2) | 12,214 (23.9) | 1476 (27.4) * |
| CO, Q1 (0.276–0.470 ppm) | 14,295 (25.3) | 13,426 (26.3) | 869 (16.1) |
| CO, Q2 (0.271–0.568 ppm) | 14,318 (25.4) | 13,113 (25.7) | 1205 (22.3) |
| CO, Q3 (0.569–0.630 ppm) | 13,745 (24.3) | 12,318 (24.1) | 1427 (26.4) |
| CO, Q4 (0.631–1.055 ppm) | 14,109 (25.0) | 12,214 (23.9) | 1895 (35.1) |
| NO2, Q1 (14.2–23.5 ppb) | 14,642 (25.9) | 13,415 (26.3) | 1227 (22.7) * |
| NO2, Q2 (23.6–29.9 ppb) | 14,269 (25.3) | 12,944 (25.3) | 1325 (24.6) |
| NO2, Q3 (30.0–36.5 ppb) | 13,439 (23.8) | 11,992 (23.5) | 1447 (26.8) |
| NO2, Q4 (36.6–51.3 ppb) | 14,117 (25.0) | 12,720 (24.9) | 1397 (25.9) |
| O3, Q1 (10.6–19.1 ppb) | 14,559 (25.8) | 12,501 (24.5) | 2058 (38.1) * |
| O3, Q2 (19.2–22.1 ppb) | 13,703 (24.3) | 11,999 (23.5) | 1704 (31.6) |
| O3, Q3 (22.2–25.5 ppb) | 14,130 (25.0) | 13,038 (25.5) | 1092 (20.2) |
| O3, Q4 (25.6–34.6 ppb) | 14,075 (24.9) | 13,533 (26.5) | 542 (10.0) |
Note: * Significantly different at a significance level of 0.05 (t-test or chi-square test).