TABLE 3.

Association of cannabis use with lung function at age 32 yrs amongst non-tobacco smokers

	Subjects n	Coefficient	95% CI	p-value
FEV1 mL	449	1.5	−16.0–19.0	0.867
FVC mL	449	17.5	−2.5–37.4	0.087
FEV1/FVC %	449	−0.19	−0.42–0.04	0.100
TLC mL	433	33.5	9.9–57.1	0.006
FRC mL	434	8.1	−13.1–29.4	0.452
RV mL	433	12.0	−0.3–24.4	0.057
Raw cmH2O·L−1·s−1	434	0.029	0.001–0.057	0.042
sGaw mL·s−1·cmH2O−1·L−1	434	−6.7	−11.8– −1.7	0.010
Tl,co mL·min−1·mmHg−1	418	0.032	−0.114–0.178	0.662
Tl,co/Va mL·min−1·  mmHg−1·L−1	418	−0.019	−0.042–0.004	0.106
Va mL	438	28.5	4.3–52.7	0.021

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 cannabis exposure as the predictor. Analyses are restricted to those without a tobacco smoking history. 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 up to age 32 yrs.