Relative risk of chronic obstructive pulmonary disease in relation to body mass index, waist circumference, hip circumference, waist–hip ratio and physical activity (NIH-AARP Diet and Health Study, 1996–2006)
| Variable | COPD cases | N | Relative risk (95% CI)* | ||||
|---|---|---|---|---|---|---|---|
| Adjusted for age and sex† | Model 1‡ | Model 1 plus BMI§ | Model 1 plus waist circumference¶ | Model 1 plus BMI and hip circumference** | |||
| BMI | |||||||
| < 18.5 | 54 | 887 | 1.76 (1.33–2.33) | 1.50 (1.12–2.03) | — | 1.56 (1.15–2.11) | — |
| 18.5–24.9 | 1 552 | 46 669 | 1.00 (ref) | 1.00 (ref) | — | 1.00 (ref) | — |
| 25.0–29.9 | 1 393 | 47 856 | 0.95 (0.88–1.02) | 0.94 (0.87–1.02) | — | 0.83 (0.76–0.91) | — |
| 30.0–34.9 | 505 | 14 386 | 1.14 (1.03–1.26) | 1.11 (1.00–1.24) | — | 0.87 (0.76–0.99) | — |
| ≥ 35.0 | 144 | 3 481 | 1.30 (1.09–1.55) | 1.36 (1.13–1.63) | — | 1.00 (0.80–1.24) | — |
| ptrend | 0.04 | 0.03 | — | 0.04 | — | ||
| Waist circumference, cm | |||||||
| < 64 (women) < 80 (men) | 35 | 1 110 | 1.09 (0.78–1.54) | 1.13 (0.79–1.61) | 1.03 (0.72–1.47) | — | 0.99 (0.69–1.42) |
| 64–79 (women) 80–93 (men) | 1 330 | 47 815 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | — | 1.00 (ref) |
| 80–87 (women) 94–101 (men) | 937 | 30 784 | 1.08 (0.99–1.18) | 1.02 (0.93–1.11) | 1.10 (1.00–1.20) | — | 1.14 (1.03–1.26) |
| 88–109 (women) 102–117 (men) | 1 185 | 30 188 | 1.36 (1.26–1.48) | 1.22 (1.12–1.33) | 1.36 (1.22–1.52) | — | 1.44 (1.28–1.63) |
| ≥ 110 (women) ≥ 118 (men) | 161 | 3 382 | 1.76 (1.48–2.08) | 1.47 (1.23–1.75) | 1.55 (1.25–1.92) | — | 1.72 (1.37–2.16) |
| ptrend | < 0.001 | < 0.001 | < 0.001 | — | < 0.001 | ||
| Hip circumference, cm | |||||||
| < 86 (women) < 87 (men) | 55 | 1 254 | 1.53 (1.16–2.02) | 1.24 (0.93–1.66) | — | 1.27 (0.95–1.70) | — |
| 86–99 (women) 87–100 (men) | 1 511 | 46 622 | 1.00 (ref) | 1.00 (ref) | — | 1.00 (ref) | — |
| 100–105 (women) 101–106 (men) | 876 | 31 334 | 0.88 (0.81–0.96) | 0.94 (0.86–1.03) | — | 0.85 (0.77–0.94) | — |
| 106–124 (women) 107–119 (men) | 1 081 | 30 486 | 1.05 (0.97–1.14) | 1.10 (1.01–1.20) | — | 0.86 (0.77–0.97) | — |
| ≥ 125 (women) ≥ 120 (men) | 125 | 3 583 | 1.09 (0.90–1.31) | 1.16 (0.96–1.41) | — | 0.78 (0.62–0.98) | — |
| ptrend | 0.6 | 0.04 | — | 0.001 | — | ||
| Waist–hip ratio | |||||||
| < 0.67 (women) < 0.82 (men) | 28 | 1 271 | 0.89 (0.61–1.29) | 0.85 (0.58–1.25) | — | — | — |
| 0.67–0.78 (women) 0.82–0.92 (men) | 1 201 | 47 687 | 1.00 (ref) | 1.00 (ref) | — | — | — |
| 0.79–0.83 (women) 0.93–0.96 (men) | 944 | 28 581 | 1.32 (1.21–1.43) | 1.18 (1.08–1.30) | — | — | — |
| 0.84–0.95 (women) 0.97–1.06 (men) | 1 303 | 32 397 | 1.59 (1.47–1.72) | 1.29 (1.18–1.40) | — | — | — |
| ≥ 0.96 (women) ≥ 1.07 (men) | 172 | 3 343 | 2.12 (1.80–2.49) | 1.46 (1.23–1.73) | — | — | — |
| ptrend | < 0.001 | < 0.001 | — | — | — | ||
| Physical activity, times/wk | |||||||
| 0 | 757 | 14 442 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | — |
| < 1 | 564 | 14 731 | 0.76 (0.68–0.85) | 0.84 (0.75–0.95) | 0.85 (0.76–0.95) | 0.85 (0.76–0.96) | — |
| 1–2 | 829 | 25 512 | 0.64 (0.58–0.71) | 0.79 (0.71–0.88) | 0.80 (0.72–0.89) | 0.81 (0.73–0.90) | — |
| 3–4 | 900 | 33 969 | 0.51 (0.46–0.56) | 0.71 (0.64–0.79) | 0.73 (0.65–0.80) | 0.74 (0.66–0.82) | — |
| ≥ 5 | 598 | 24 625 | 0.47 (0.42–0.52) | 0.67 (0.60–0.75) | 0.68 (0.61–0.77) | 0.71 (0.63–0.79) | — |
| ptrend | < 0.001 | < 0.001 | < 0.001 | < 0.001 | — | ||
BMI = body mass index, CI = confidence interval, COPD = chronic obstructive pulmonary disease, NIH = National Institutes of Health.
↵* Unless stated otherwise.
↵† Adjusted for age (5-year groups) and sex (female, male).
↵‡ Adjusted for age (5-year groups), sex (female, male), marital status (married or common law, never married, separated, divorced, widowed), education (high school or less than high school, vocational training or some college, college education, postgraduate education), ethnicity (non-Hispanic white, non-Hispanic black, Hispanic, Asian, other ethnic background), alcohol intake (0, 0.1–14.9, 15.0–29.9, 30.0–59.9, ≥ 60 g/d), 31 combinations of smoking status (currently smoking, stopped smoking within the last 12 months, stopped smoking 1–4 years ago, stopped smoking 5–9 years ago, stopped smoking ≥ 10 years ago, never smoked) and smoking intensity (never smoked: 0 cigarettes/d; ever smoked: 1–10, 11–20, 21–30, 31–40, 41–60, ≥ 61 cigarettes/d), history of type 2 diabetes mellitus (no, yes) and height (sex-specific quintiles). The BMI, waist circumference and waist–hip ratio analyses were additionally adjusted for physical activity (0, < 1, 1–2, 3–4,
↵≥ 5 times/wk).
↵§ Additionally adjusted for BMI (< 18.5, 18.5–24.9, 25.0–29.9, 30.0–34.9, ≥ 35.0).
↵¶ Additionally adjusted for waist circumference (women: < 64, 64–79, 80–87, 88–109, ≥ 110 cm; men: < 80, 80–93, 94–101, 102–117, ≥ 118 cm).
↵** Additionally adjusted for BMI (< 18.5, 18.5–24.9, 25.0–29.9, 30.0–34.9, ≥ 35.0) and hip circumference (women: < 86, 86–99, 100–105, 106–124, ≥ 125 cm; men: < 87, 87–100, 101–106, 107–119, ≥ 120 cm).