Table 1.
Demographic characteristics of high-altitude residents by altitude and gender: anthropometric data, education, smoking history, risk factors and results of pulmonary function tests.
| Variables | Total (n = 4,967) | Men (n = 2,415) | Women (n = 2,552) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2,100–3,000 m (n = 1,626) | 3,000–4,000 m (n = 1,895) | >4,000 m (n = 1,446) | P-value | 2,100–3,000 m (n = 807) | 3,000–4,000 m (n = 956) | >4,000 m (n = 652) | P-value | 2,100–3,000 m (n = 819) | 3,000–4,000 m (n = 939) | >4,000 m (n = 794) | P-value | |
| Age, years | ||||||||||||
| 15–39 | 898 (55.3%) | 1,038 (54.7%) | 723 (50.0%) | <0.0001 | 462 (57.2%) | 605 (63.3%) | 335 (51.4%) | <0.0001 | 436 (53.2%) | 433 (46.1%) | 388 (48.9%) | 0.002 |
| 40–49 | 348 (21.4%) | 382 (20.2%) | 382 (26.4%) | 162 (20.1%) | 158 (16.5%) | 175 (26.8%) | 186 (22.7%) | 224 (23.9%) | 207 (26.1%) | |||
| 50–59 | 233 (14.3%) | 271 (14.3%) | 247 (17.1%) | 104 (12.9%) | 104 (10.9%) | 105 (16.1%) | 129 (15.8%) | 167 (17.8%) | 142 (17.9%) | |||
| ≥60 | 147 (9.0%) | 204 (10.8%) | 94 (6.5%) | 79 (9.8%) | 89 (9.3%) | 37 (5.7%) | 68 (8.3%) | 115 (12.2%) | 57 (7.2%) | |||
| Body-mass index, kg/m2 | 23.4 (3.7) | 23.7 (3.9) | 24.0 (4.2) | <0.0001 | 23.3 (3.6) | 23.5 (3.5) | 24.0 (4.0) | 0.001 | 23.4 (3.8) | 23.9 (4.4) | 24.0 (4.3) | 0.022 |
| Education level | ||||||||||||
| Primary school and lower | 812 (49.9%) | 863 (45.5%) | 993 (68.7%) | <0.0001 | 332 (41.1%) | 295 (30.9%) | 421 (64.6%) | <0.0001 | 480 (58.6%) | 568 (60.5%) | 572 (72.0%) | <0.0001 |
| Middle and high school | 608 (37.4%) | 473 (25.0%) | 245 (16.9%) | 341 (42.3%) | 280 (29.3%) | 126 (19.3%) | 267 (32.6%) | 193 (20.6%) | 119 (15.0%) | |||
| College and higher | 206 (12.7%) | 559 (29.5%) | 208 (14.4%) | 134 (16.6%) | 381 (39.9%) | 105 (16.1%) | 72 (8.8%) | 178 (19.0%) | 103 (13.0%) | |||
| Smoking status | ||||||||||||
| Never smoker | 1,071 (65.9%) | 1,371 (72.3%) | 1,162 (80.4%) | <0.0001 | 317 (39.3%) | 445 (46.5%) | 471 (72.2%) | <0.0001 | 754 (92.1%) | 926 (98.6%) | 691 (87.0%) | <0.0001 |
| Former smoker | 112 (6.9%) | 81 (4.3%) | 107 (7.4%) | 101 (12.5%) | 76 (8.0%) | 60 (9.2%) | 11 (1.3%) | 5 (0.5%) | 47 (5.9%) | |||
| Current smoker | 443 (27.2%) | 443 (23.4%) | 177 (12.2%) | 389 (48.2%) | 435 (45.5%) | 121 (18.6%) | 54 (6.6%) | 8 (0.9%) | 56 (7.1%) | |||
| Cigarette smoking, pack-year* | ||||||||||||
| 0 | 1,071 (65.9%) | 1,371 (72.5%) | 1,162 (80.6%) | <0.0001 | 317 (39.4%) | 445 (46.7%) | 471 (72.6%) | <0.0001 | 754 (92.1%) | 926 (98.7%) | 691 (87.0%) | <0.0001 |
| 1–19 | 19 (1.2%) | 50 (2.6%) | 68 (4.7%) | 17 (2.1%) | 49 (5.1%) | 47 (7.3%) | 2 (0.2%) | 1 (0.1%) | 21 (2.6%) | |||
| ≥20 | 534 (32.9%) | 470 (24.9%) | 212 (14.7%) | 471 (58.5%) | 459 (48.2%) | 130 (20.1%) | 63 (7.7%) | 11 (1.2%) | 82 (10.3%) | |||
| Risk factors for COPD | ||||||||||||
| Household air pollution* | 1,356 (83.4%) | 1,070 (56.5%) | 944 (66.0%) | <0.0001 | 626 (77.6%) | 472 (49.4%) | 408 (63.6%) | <0.0001 | 730 (89.1%) | 598 (63.7%) | 536 (67.9%) | <0.0001 |
| History of tuberculosis | 82 (5.0%) | 122 (6.4%) | 50 (3.5%) | 0.001 | 40 (5.0%) | 52 (5.4%) | 27 (4.1%) | 0.497 | 42 (5.1%) | 70 (7.5%) | 23 (2.9%) | <0.0001 |
| Exposure to dust or chemicals in the workplace* | 14 (0.9%) | 109 (5.9%) | 15 (1.0%) | <0.0001 | 8 (1.0%) | 54 (5.8%) | 10 (1.5%) | <0.0001 | 6 (0.7%) | 55 (6.0%) | 5 (0.6%) | <0.0001 |
| Spirometry,% | ||||||||||||
| Pre-BD FEV1/FVC | 79.34 (10.07) | 84.38 (9.84) | 84.56 (10.26) | <0.0001 | 79.10 (10.40) | 84.61 (9.94) | 84.36 (9.96) | <0.0001 | 79.58 (9.74) | 84.16 (9.73) | 84.72 (10.50) | <0.0001 |
| Post-BD FEV1/FVC | 81.7 (10.0) | 85.75 (9.30) | 85.75 (9.47) | <0.0001 | 81.20 (10.41) | 86.05 (9.23) | 85.19 (10.14) | <0.0001 | 82.24 (9.57) | 85.45 (9.37) | 86.21 (8.86) | <0.0001 |
| Pre-BD FVC %predicted | 79.33 (10.08) | 84.37 (9.84) | 84.55 (10.26) | <0.0001 | 79.08 (10.40) | 84.60 (9.94) | 84.36 (9.96) | <0.0001 | 79.57 (9.75) | 84.14 (9.73) | 84.71 (10.51) | <0.0001 |
| Post-BD FVC %predicted | 82.07 (11.45) | 85.88 (13.05) | 86.25 (22.25) | <0.0001 | 81.75 (11.60) | 86.43 (13.36) | 85.00 (15.15) | <0.0001 | 82.38 (11.29) | 85.33 (12.71) | 87.28 (26.68) | <0.0001 |
| Pre-BD FEV1 %predicted | 104.11 (13.47) | 102.22 (15.02) | 102.36 (24.07) | 0.003 | 104.06 (13.68) | 102.70 (16.51) | 100.92 (14.76) | <0.0001 | 104.15 (13.26) | 101.74 (13.32) | 103.55 (29.56) | 0.029 |
| Post-BD FEV1 %predicted | 103.70 (11.74) | 102.26 (12.30) | 102.42 (15.76) | 0.003 | 103.37 (11.74) | 102.41 (12.67) | 101.65 (13.80) | 0.034 | 104.03 (11.75) | 102.12 (11.93) | 103.05 (17.19) | 0.014 |
| Oxyhemoglobin saturation, % | 93.5 (3.3) | 90.6 (5.1) | 86.3 (4.5) | <0.0001 | 93.1 (3.1) | 90.6 (4.9) | 86.2 (4.6) | <0.0001 | 94.0 (3.3) | 90.6 (5.3) | 86.4 (4.4) | <0.0001 |
Data are expressed as number (%) or mean (standard deviation, SD). COPD, chronic obstructive pulmonary disease; FVC, forced vital capacity; FEV1, forced expiratory volume in the first second; Pre-BD, pre-bronchodilator; Post-BD, post-bronchodilator.
*
assessed in Cigarette smoking with data missing for 10 participants, household air pollution with data missing for 15 participants and exposure to dust or chemicals in the workplace with data missing for 38 participants.