Lung function according to BMI quintile
| BMI quintile 1 | BMI quintile 2 | BMI quintile 3 | BMI quintile 4 | BMI quintile 5 | p value for trend | |
|---|---|---|---|---|---|---|
| *Results are reported as mean with 95% confidence intervals. | ||||||
| **Results are reported as prevalence with 95% confidence intervals. | ||||||
| FEV1 = forced expiratory volume in 1 second; FVC = forced vital capacity; PEFR = peak expiratory flow rate; FEF25–75 = mid forced expiratory flow; DRR = dose response ratio ((% fall in FEV1/dose of histamine) + 3); AHR = airway hyperresponsiveness. | ||||||
| FEV1 (% predicted)* | ||||||
| Boys | 101.9 (101.0 to 102.8) | 104.3 (103.4 to 105.2) | 105.6 (104.7 to 106.5) | 105.4 (104.4 to 106.3) | 106.1 (105.2 to 107.0) | <0.01 |
| Girls | 106.7 (105.7 to 107.7) | 109.3 (108.3 to 110.3) | 109.5 (108.5 to 110.4) | 110.4 (109.4 to 111.4) | 111.0 (110.0 to 112.1) | <0.01 |
| FVC (% predicted)* | ||||||
| Boys | 98.5 (97.7 to 99.4) | 101.8 (100.9 to 102.7) | 103.1 (102.1 to 104.0) | 103.3 (102.4 to 104.2) | 104.2 (103.2 to 105.1) | <0.01 |
| Girls | 102.0 (101.2 to 102.8) | 104.7 (103.9 to 110.3) | 105.5 (104.6 to 106.4) | 107.2 (106.3 to 108.1) | 107.4 (106.5 to 108.3) | <0.01 |
| FEV1/FVC%* | ||||||
| Boys | 90.7 (90.2 to 91.1) | 89.7 (89.2 to 90.2) | 89.8 (89.3 to 90.2) | 89.2 (88.7 to 89.6) | 89.0 (88.5 to 89.4) | <0.01 |
| Girls | 92.8 (92.4 to 93.2) | 92.3 (91.9 to 92.7) | 92.1 (91.7 to 92.5) | 91.2 (90.8 to 91.6) | 91.6 (91.2 to 92.0) | <0.01 |
| PEFR (% predicted)* | ||||||
| Boys | 88.0 (86.7 to 89.3) | 89.5 (88.0 to 90.9) | 88.7 (87.4 to 90.1) | 89.1 (87.8 to 90.4) | 88.7 (87.4 to 90.1) | 0.75 |
| Girls | 91.2 (89.5,92.8) | 93.3 (91.7 to 94.9) | 93.2 (91.6 to 94.7) | 93.6 (92.1 to 95.2) | 94.7 (93.1 to 96.3) | 0.04 |
| FEF25–75 (% predicted)* | ||||||
| Boys | 94.2 (92.5 to 95.9) | 94.2 (92.4 to 95.9) | 94.7 (93.1 to 96.3) | 93.5 (91.8 to 95.1) | 94.6 (92.9 to 96.3) | 0.81 |
| Girls | 98.2 (96.5 to 100.0) | 99.4 (97.7 to 101.2) | 100.6 (98.8 to 102.5) | 99.7 (97.8 to 101.6) | 103.2 (101.3 to 105.1) | |
| DRR* | ||||||
| Boys | 5.92 (5.51 to 6.37) | 6.32 (5.84 to 6.84) | 5.80 (5.41 to 6.23) | 5.70 (5.35 to 6.06) | 5.71 (5.35 to 6.09) | 0.21 |
| Girls | 4.81 (4.50 to 5.15) | 4.96 (4.67 to 5.26) | 4.93 (4.63 to 5.24) | 4.95 (4.67 to 5.24) | 4.86 (4.59 to 5.14) | 0.95 |
| AHR (DRR >8.1)** | ||||||
| Boys | 22.7 (19.4 to 26.0) | 23.5 (20.1 to 26.9) | 22.0 (18.6 to 25.4) | 22.1 (18.9 to 25.3) | 21.2 (17.9 to 24.5) | 0.41 |
| Girls | 16.3 (13.3 to 19.3) | 15.1 (12.2 to 18.0) | 15.2 (12.4 to 18.0) | 16.6 (13.6 to 19.6) | 14.8 (12.0 to 17.7) | 0.92 |