1987 | 2008 | p Value | |
Age (years) | 18.4±3.2 | 38.1±3.2 | |
BMI (kg/m2) | 21.0±2.8 | 24.4±4.4 | <0.01 |
TLC (L) | 5.49±1.16 | 7.02±1.45 | <0.01 |
TLC (% predicted) | 96.1±12.1 | 112.7±16.4 | 0.04 |
FRC (L) | 2.70±0.62 | 3.27±0.84 | 0.04 |
FRC (% predicted) | 95.2±10.7 | 103.3±27.1 | NS |
RV (%) | 108.2±26.5 | 150.6±40.8 | <0.01 |
RV/TLC | 25.9±7.0 | 39.3±6.8 | <0.01 |
FEV1 (L/sec) | 3.10±0.8 | 2.95±0.88 | NS |
FEV1 (z-score) | −1.8±1.7 | −1.8±1.2 | NS |
FVC (L) | 4.15±1.01 | 4.1±1.15 | NS |
FVC (z-score) | −1.2±1.2 | −1.7±1.3 | NS |
FEV1/FVC (%) | 72.6±9.1 | 69.9±9.9 | NS |
FEV1/FVC (z-score) | −1.7±0.8 | −1.3±0.9 | NS |
MEF50 (L/min) | 2.98±0.91 | 2.70±1.03 | NS |
MEF50 (z-score) | −1.61±1.02 | −1.46±0.77 | NS |
MEF25 (L/min) | 1.48±0.77 | 1.19±0.70 | NS |
MEF25 (z-score) | −1.27±0.98 | −0.93±0.61 | NS |
Shift of mean difference 1987–2008 | 95% CI | p Value | |
FVC (L) | −0.584 | −1.092 to −0.076 | 0.03 |
FEV1 (L/sec) | −0.367 | −0.971 to 0.237 | NS |
FEV1/FVC | 0.003 | −0.138 to 0.143 | NS |
Numbers indicate means±SD.
FEV1, forced expiratory volume in the first second; FRC, functional residual capacity; FVC, forced vital capacity; MEF25, 50, maximum expiratory flows at 25% and 50% of vital capacity; RV, residual volume; TLC, total lung capacity.