Table 2.
Effect of body mass index on COPD development according to the Asian body mass index category.
| BMI (kg/m2) | n | COPD | Duration (PY) | IR (per 1000 PY) | Adjusted hazard ratio (95% confidence interval) | |||
|---|---|---|---|---|---|---|---|---|
| Model 1 | Model 2 | Model 3 | Model 4 | |||||
| Total | ||||||||
| < 18.5 | 479,465 | 1,176 | 3,974,896.84 | 0.2959 | 1.195 (1.123, 1.272) | 1.383 (1.298, 1.474) | 1.371 (1.286, 1.460) | 1.370 (1.286, 1.460) |
| 18.5–22.9 | 2,950,675 | 6,099 | 24,614,001.13 | 0.2478 | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) |
| 23.0–24.9 | 1,208,895 | 2,572 | 10,150,626.96 | 0.2534 | 1.021 (0.975, 1.070) | 0.907 (0.865, 0.951) | 0.905 (0.864, 0.949) | 0.901 (0.860, 0.945) |
| 25.0–29.9 | 1,397,745 | 3,176 | 11,726,278.97 | 0.2708 | 1.092 (1.046, 1.140) | 0.933 (0.892, 0.976) | 0.916 (0.876, 0.958) | 0.895 (0.854, 0.938) |
| ≥ 30.0 | 267,989 | 761 | 2,209,332.13 | 0.3445 | 1.393 (1.292, 1.502) | 1.256 (1.164, 1.355) | 1.178 (1.091, 1.271) | 1.112 (1.023, 1.208) |
| Male* | ||||||||
| < 18.5 | 99,928 | 477 | 832,853.66 | 0.5727 | 2.040 (1.853, 2.246) | 2.194 (1.993, 2.416) | 2.108 (1.914, 2.322) | 2.114 (1.919, 2.328) |
| 18.5–22.9 | 1,364,031 | 3,228 | 11,474,060.06 | 0.2813 | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) |
| 23.0–24.9 | 908,734 | 1,924 | 7,674,981.37 | 0.2507 | 0.890 (0.841, 0.942) | 0.824 (0.779, 0.872) | 0.831 (0.785, 0.879) | 0.826 (0.780, 0.874) |
| 25.0–29.9 | 1,152,716 | 2,523 | 9,717,014.52 | 0.2597 | 0.922 (0.875, 0.972) | 0.823 (0.781, 0.867) | 0.818 (0.776, 0.862) | 0.796 (0.753, 0.841) |
| ≥ 30.0 | 207,247 | 550 | 1,717,774.77 | 0.3202 | 1.141 (1.042, 1.249) | 1.073 (0.981, 1.175) | 1.033 (0.943, 1.130) | 0.968 (0.877, 1.068) |
| Female* | ||||||||
| < 18.5 | 379,537 | 699 | 3,142,043.18 | 0.2225 | 1.018 (0.938, 1.106) | 1.107 (1.019, 1.203) | 1.101 (1.013, 1.197) | 1.102 (1.014, 1.198) |
| 18.5–22.9 | 1,586,644 | 2,871 | 13,139,941.07 | 0.2185 | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) | 1 (Ref.) |
| 23.0–24.9 | 300,161 | 648 | 2,475,645.59 | 0.2618 | 1.198 (1.100, 1.305) | 1.118 (1.026, 1.218) | 1.097 (1.007, 1.195) | 1.091 (1.001, 1.188) |
| 25.0–29.9 | 245,029 | 653 | 2,009,264.45 | 0.3250 | 1.489 (1.367, 1.621) | 1.373 (1.261, 1.496) | 1.300 (1.193, 1.416) | 1.264 (1.157, 1.381) |
| ≥ 30.0 | 60,742 | 211 | 491,557.36 | 0.4293 | 1.969 (1.712, 2.265) | 1.885 (1.639, 2.168) | 1.629 (1.415, 1.874) | 1.494 (1.279, 1.745) |
Model 1: non-adjusted.
Model 2: adjusted for age and sex.
Model 3: adjusted for age, sex, smoking, alcohol consumption, regular exercise, asthma, and pneumonia.
Model 4: adjusted for age, sex, smoking, alcohol consumption, regular exercise, asthma, pneumonia, and metabolic syndrome.
*Sex was excluded from multivariate models.
BMI: body mass index; COPD: chronic obstructive pulmonary disease; PY: person-year; IR: incidence rate; Ref.: reference.