Division of Pulmonary and Critical Care Medicine, Department of Medicine, David Geffen School of Medicine at UCLA Health Sciences, Los Angeles, Calif.
Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Kelowna, BC, Canada.
J Allergy Clin Immunol Pract. 2022 Nov;10(11):2822-2829. doi: 10.1016/j.jaip.2022.05.009. Epub 2022 May 21.
Although vaping has recently increased as a mode of inhaling marijuana and has been associated with numerous and sometimes fatal cases of acute severe lung injury, smoking remains the most common method of inhaling marijuana and has been studied more extensively. Smoking marijuana has been shown to produce modest but significant short-term bronchodilation both in healthy subjects and in those with asthma. Long-term effects of habitual marijuana smoking include the following: (1) symptoms of chronic bronchitis (increased cough, sputum production, and wheezing); (2) modest effects on lung function in cross-sectional studies (no significant decrease in FEV but mild reductions in FEV/forced vital capacity ratio, an increase in forced vital capacity and other lung volumes, reductions in specific airway conductance, and variable effects of maximal midexpiratory flow rates and diffusing capacity); and (3) variable effects on age-related decline in FEV in longitudinal studies. Most cohort and case-control studies have failed to show that marijuana smoking is a significant risk factor for lung cancer despite the presence of procarcinogenic components in marijuana smoke, although further study is warranted. The question whether marijuana smoking is associated with asthma is unclear and requires further investigation. Although delta-9 tetrahydrocannabinol, the principal psychoactive component of marijuana, has immunomodulatory properties that hypothetically could increase the risk of pneumonia, the few available studies in marijuana smokers have failed to find an increased risk of pneumonia in immunocompetent users, although effects in immunosuppressed individuals have been variable.
尽管蒸气吸入作为一种吸食大麻的方式最近有所增加，并与许多有时甚至是致命的急性严重肺部损伤病例有关，但吸烟仍然是吸食大麻最常见的方式，并且已经进行了更广泛的研究。吸烟大麻已被证明在健康受试者和哮喘患者中均能产生适度但显著的短期支气管扩张作用。习惯性吸食大麻的长期影响包括以下几点：（1）慢性支气管炎的症状（咳嗽，咳痰和喘息增加）；（2）在横断面研究中对肺功能有适度影响（FEV 无明显下降，但 FEV/用力肺活量比略有下降，用力肺活量和其他肺容积增加，气道传导率下降，最大中期呼气流量和弥散量的可变作用）；（3）在纵向研究中对 FEV 随年龄下降的影响具有可变性。尽管大麻烟雾中存在致癌成分，但大多数队列研究和病例对照研究均未能表明大麻吸烟是肺癌的重要危险因素，尽管如此，仍需要进一步研究。大麻吸烟是否与哮喘有关尚不清楚，需要进一步调查。尽管大麻中的主要精神活性成分Δ-9-四氢大麻酚具有免疫调节特性，理论上可能会增加肺炎的风险，但在大麻吸烟者中进行的少数几项可用研究并未发现免疫功能正常的使用者中肺炎的风险增加，尽管对免疫抑制个体的影响是可变的。
