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A3579 - Impact of Habitual Marijuana Smoking on Lung Disease in a Country with Legal Cannabis Production
Author Block: L. Fernandez1, J. Soto1, A. Aleman2, A. Liencres1, L. Romero1, V. Torres1, M. Gutierrez1; 1Hospital Maciel. Cátedra Neumología, Montevideo, Uruguay, 2Facultad de Medicina. Medicina Preventiva y Social, Montevideo, Uruguay.
Introduction: Marijuana is the most consumed illicit drug worldwide and the second most frequent smoked substance after tobacco. The combustion products of cannabis and tobacco share substances with detrimental effect on the respiratory system. Numerous studies have been conducted to assess whether smoked cannabis produces adverse effects similar to those produced by tobacco; however accurate study of the adverse effects of marijuana is difficult to perform, owing in part to marijuana’s illegal status. Uruguay was the first country to legalize cannabis production and distribution. Our objective is to study the clinical and spirometry characteristics in a group of habitual cannabis users, in the framework of legality that the legislation of Uruguay allows. Materials and methods: 50 habitual cannabis smokers belonging to a cannabis membership club of Montevideo were enrolled. Participants completed questionnaires about inhaled drug use and respiratory symptoms. Additionally, baseline and post-bronchodilator spirometry was performed. Results: Of the 50 participants, 45 (90%) are men, the average age was 36.6 years (range 21-64 years). The average lifetime history of cannabis consumption was 24 joint-years. Considering tobacco compsumtion, 56% (IC95% 42 - 71) were current smokers with an average pack-years of 14; 24% (IC95% 11-37) were former smokers, and 22% (IC95% 9 - 34) were never tobacco smokers. Regarding the prevalence of respiratory symptoms, 34% (IC95% 20 - 48) reported morning cough, 22% (IC95% 9 - 34) presented dyspnea and 40%(IC95% 25 - 54) had wheezing. Spirometry showed that 56% (IC95% 42 - 71) had a FVC greater than 120% of predicted. All participants had FEV1 greater than 80% of predicted, and only 2 consumers had a FEV1/FVC less than 0.7. Discussion and conclusion: The subjects analyzed were habitual cannabis users with heavy cumulative consumption, defined as a lifetime smoking history greater than 20 joint-years. The study showed high prevalence of respiratory symptoms such as cough, dyspnea and wheezing. Considering spirometry results, a FVC greater than 120% in most consumers is highlighted, which has been linked to the pulmonary stretch secondary to the pattern of deep inhalation of cannabis smokers. There was no evidence of airflow obstruction in most of the participants. Although the findings are similar to those reported in previous studies, a greater number of participants are needed to confirm the respiratory repercussions in heavy cannabis smokers.