Effects of smoking cannabis on lung function

Figures & data

Table 1. Epidemiological associations between cannabis use and lung function.

Study (year)	Study design	Subjects (n)	Results	Ref.
Hancox et al. (2010)	Observational cohort	919	Increased lung capacity and airway resistance in marijuana smokers. No evidence of airway obstruction, gas trapping or impaired gas transfer	[18]
Tan et al. (2009)	Observational cohort	878	Marijuana smoking not associated with increased bronchitic symptoms and COPD	[17]
Sherrill et al. (1991)	Observational cohort	856	Pulmonary function was reduced in subjects reporting marijuana smoking	[50]
Tashkin et al. (1997)	Observational cohort	394	No effect of marijuana smoking on FEV1 decline	[51]
Aldington et al. (2007)	Cross-sectional	339	Marijuana associated with airflow obstruction, hyperinflation and large airways impairment	[11]
Bloom et al. (1987)	Cross-sectional	990	No effect of marijuana on FEV1 or FVC	[45]
Cruickshank (1976)	Cross-sectional	60	No difference between marijuana smokers and controls	[46]
Hernandez et al. (1981)	Cross-sectional	23	Normal spirometry in marijuana smokers	[47]
Moore et al. (2005)	Cross-sectional	6728	Marijuana use not associated with decreased FEV1/FVC ratio	[48]
Sherman et al. (1991)	Cross-sectional	63	No significant difference in FEV1/FVC and DLco in marijuana smokers and nonsmokers	[49]
Tashkin et al. (1980)	Cross-sectional	189	Marijuana smokers had lower sGaw compared with controls (p < 0.001)	[21]
Tashkin et al. (1993)	Cross-sectional	542	Marijuana smoking associated with airway hyper-responsiveness with lose-dose methacholine	[52]
Tilles et al. (1986)	Cross-sectional	68	Marijuana smoking regardless of tobacco smoking, resulted in reduction of single breath DLco compared with nonsmokers	[53]
Tashkin et al. (1987)	Cross-sectional	446	Male marijuana smokers had reduced sGaw compared with male tobacco smokers. No difference in DLco	[20]
Total:		12,613

Taylor et al. performed two studies (2000 [8] and 2002 [19]) on the same cohort that have been superseded by Hancox et al.[18].

COPD: Chronic obstructive pulmonary diease; DL_co: Diffusing capacity for carbon monoxide; FEV₁: Forced expiratory volume after 1 s; FVC: Forced vital capacity; sGaw: Specific airway conductance.

Table 2. Reports of bullous lung disease in cannabis users.

Study (year)	Pateints (n)	Mean age (years)	Mean joint-years	Results	Ref.
Beshay et al. (2007)	17	27	53	Upper lobe predominance with bullae ranging from 0.3 to 12 cm	[23]
Johnson et al. (2000)	4	38	NS	All had upper lobe bullae and normal lower lobes	[40]
Gao et al. (2010)	1	23	NS	Bilateral upper lobe bullae, more prominent on the right	[41]
Hii et al. (2008)	10	41	74	Upper and mid-zone emphysematous bullae	[42]
Phan et al. (2005)	1	26	>10	Extensive cystic and bullous lung changes primarily affecting lower lobes	[43]
Thompson et al. (2002)	3	39	NS	Large apical lung bullae	[44]

NS: Not stated.

Table 3. Differences in lung function associated with cannabis and tobacco use.

Measure	Cannabis	Tobacco
FEV1	↔	↔/↓
FVC	↑	↔
FEV1/FVC ratio	↔	↓
TLC	↑	↔/↑
RV	↑	↑
DLco	↔	↓
sGaw	↓	↔/↓

↔: No association; ↑: Increase; ↓: Decrease.

DL_co: Diffusing capacity for carbon monoxide; FEV₁: Forced expiratory volume; FVC: Forced vital capacity; RV: Residual volume; sGaw: Specific airway conductance; TLC: Total lung capacity.

Data taken from [18].

Table

Activity Evaluation
Where 1 is strongly disagree and 5 is strongly agree
	1	2	3	4	5
1. The activity supported the learning objectives.
2. The material was organized clearly for learning to occur.
3. The content learned from this activity will impact my practice.
4. The activity was presented objectively and free of commercial bias.

Hancox RJ, Poulton R, Ely M et al. Effects of marijuana on lung function: a population-based cohort study. Eur. Respir. J.35(1), 42–47 (2010).

 PubMed Web of Science ®Google Scholar

Tan WC, Lo C, Jong A et al. Marijuana and chronic obstructive lung disease: a population-based study. CMAJ180(8), 814–820 (2009).

 PubMed Web of Science ®Google Scholar

Sherrill DL, Krzyzanowski M, Bloom JW et al. Respiratory effects of non-tobacco cigarettes: a longitudinal study in general population. Int. J. Epidemiol.20, 132–137 (1991).

 PubMed Web of Science ®Google Scholar

Tashkin DP, Simmons MS, Sherrill DL et al. Heavy habitual marijuana smoking does not cause an accelerated decline in FEV1 with age. Am. J. Respir. Crit. Care Med.155, 141–148 (1997).

 PubMed Web of Science ®Google Scholar

Aldington S, Williams M, Nowitz M et al. Effects of marijuana on pulmonary structure, function and symptoms. Thorax62(12), 1058–1063 (2007).

 PubMed Web of Science ®Google Scholar

Bloom JW, Kaltenborn WT, Paoletti P et al. Respiratory effects of non-tobacco cigarettes. Br. Med. J. (Clin. Res. Ed.)295, 1516–1518 (1987).

 PubMed Web of Science ®Google Scholar

Cruickshank EK. Physical Assessment of 30 chronic cannabis users and 30 matched controls. Ann. NY Acad. Sci.282, 162–167 (1976).

 Google Scholar

Hernandez MJ, Martinez F, Blair HT et al. Airway response to inhaled histamine in asymptomatic long-term marijuana smokers. J. Allergy Clin. Immunol.67, 153–155 (1981).

 Google Scholar

Moore BA, Augustson EM, Moser RP et al. Respiratory effects of marijuana and tobacco use in a US sample. J. Gen. Intern. Med.20, 33–37 (2005).

 PubMed Web of Science ®Google Scholar

Sherman MP, Roth MD, Gong H Jr et al. Marijuana smoking, pulmonary function, and lung macrophage oxidant release. Pharmacol. Biochem. Behav.40, 663–669 (1991).

 PubMed Web of Science ®Google Scholar

Tashkin DP, Calvarese BM, Simmons MS et al. Respiratory status of seventy-four habitual marijuana smokers. Chest78(5), 699–706 (1980).

 PubMed Web of Science ®Google Scholar

Tashkin DP, Simmons MS, Chang P et al. Effects of smoked substance abuse on non-specific airway hyperresponsiveness. Am. Rev. Respir. Dis.147, 97–103 (1993).

 PubMed Web of Science ®Google Scholar

Tilles DS, Goldenheim PD, Johnson DC et al. Marijuana smoking as a cause of reduction in single-breath carbon monoxide diffusing capacity. Am. J. Med.80, 601–606 (1986).

 PubMed Web of Science ®Google Scholar

Tashkin DP, Coulson AH, Clark VA et al. Respiratory symptoms and lung function in habitual heavy smokers of marijuana alone, smokers of marijuana and tobacco, smokers of tobacco alone, and nonsmokers. Am. Rev. Respir. Dis.135(1), 209–216 (1987).

 PubMed Web of Science ®Google Scholar

Hoffmann D, Brunnemann KD, Gori GB et al. On the carcinogenicity of marijuana smoke. Recent Adv. Phytochem.9, 63–81 (1975).

 Google Scholar

Taylor DR, Fergusson DM, Milne BJ et al. A longitudinal study of the effects of tobacco and marijuana exposure on lung function in young adults. Addiction97, 1055–1061 (2002).

 PubMed Web of Science ®Google Scholar

Beshay M, Kaiser H, Niedhart D et al. Emphysema and secondary pneumothorax in young adults smoking marijuana. Eur. J. Cardiothorac. Surg.32(6), 834–838 (2007).

 PubMedGoogle Scholar

Johnson MK, Smith RP, Morrison D et al. Large lung bullae in marijuana smokers. Thorax55, 340–342 (2000).

 PubMed Web of Science ®Google Scholar

Gao Z, Wood-Baker R, Harle R et al. ‘Bong lung’ in cystic fibrosis: a case report. J. Med. Case Rep.4, 371 (2010).

 Google Scholar

Hii S, Tam J, Thompson B et al. Bullous lung disease due to marijuana. Respirology13, 122–127 (2008).

 Google Scholar

Phan TD, Lau KK, Li X. Lung bullae and pulmonary fibrosis associated with marijuana smoking. Australas. Radiol.49, 411–414 (2005).

 Google Scholar

Thompson CS, White RJ. Lung bullae and marijuana. Thorax57, 563 (2002).

 PubMed Web of Science ®Google Scholar