Associations of cannabis and tobacco use with lung function at age 32 yrs
| Subjects n | Cannabis | Tobacco | |||||
| Coefficient | 95% CI | p-value | Coefficient | 95% CI | p-value | ||
| FEV1 mL | 919 | 4.0 | -3.7–11.8 | 0.311 | -5.0 | -10.3–0.2 | 0.061 |
| FVC mL | 919 | 12.0 | 3.0–21.0 | 0.009 | 0.1 | -6.0–6.2 | 0.968 |
| FEV1/FVC % | 919 | -0.08 | -0.18–0.02 | 0.127 | -0.11 | -0.18– -0.04 | 0.003 |
| TLC mL | 883 | 25.0 | 13.9–36.0 | <0.001 | 7.4 | -0.2–14.9 | 0.057 |
| FRC mL | 884 | 15.1 | 4.8–25.4 | 0.004 | 10.5 | 3.5–17.6 | 0.003 |
| RV mL | 883 | 12.6 | 7.0–18.3 | <0.001 | 6.3 | 2.4–10.1 | 0.002 |
| Raw cmH2O·L−1·s−1 | 884 | 0.014 | 0.002–0.026 | 0.024 | -0.001 | -0.01–0.01 | 0.827 |
| sGaw mL·s−1·cmH2O−1·L−1 | 884 | -3.3 | -5.5– -1.0 | 0.005 | -1.5 | -3.0–0.01 | 0.059 |
| TL,CO mL·min−1·mmHg−1 | 841 | -0.019 | -0.09–0.05 | 0.589 | -0.130 | -0.19– -0.07 | <0.001 |
| TL,CO/VA mL·min−1·mmHg−1·L−1 | 841 | -0.016 | -0.03– -0.01 | 0.003 | -0.023 | -0.03– -0.01 | <0.001 |
| VA mL | 894 | 17.8 | 6.8–28.9 | 0.002 | 2.3 | -5.2–9.9 | 0.545 |
FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; TLC: total lung capacity; FRC: functional residual capacity; RV: residual volume; Raw: airway resistance; sGaw: specific airway conductance; TL,CO: transfer factor of the lung for carbon monoxide; VA: alveolar volume. Linear regression analyses of lung function at age 32 yrs using both cannabis and tobacco exposures as predictors. All analyses adjusted for sex and, except for FEV1/FVC and sGaw, for height. Analyses of TL,CO also adjust for exhaled carbon monoxide and blood haemoglobin. Coefficients represent the difference in lung function associated with each joint-year of cannabis or pack-year of tobacco up to age 32 yrs, adjusted for use of the other substance.