大麻吸食者可能更早出现肺气肿 对比吸烟者

Signs of emphysema may develop early in pot smokers

NEW YORK (Reuters Health) - Pot smokers may experience pathological changes in their lungs decades earlier than such changes usually occur in cigarette smokers, a small study of 10 patients shows.

The patients' average age was 41 years and they reported smoking marijuana regularly for at least 1 year. The main feature in all patients was air pockets in the lungs known as bullae, which are typically seen in people with emphysema that develops after many years of cigarette smoking.

About 15 percent of cigarette smokers will develop emphysema by age 65, but less is known about the effects of marijuana on the lungs, Dr. Su W. Hii of Monash University in Victoria, Australia and colleagues note. Because pot smokers typically inhale hot smoke forcefully and hold it in their lungs for as long as possible, the researchers add, it's possible that they may be doing more damage to their lung tissue.

To investigate, Hii and colleagues evaluated 10 marijuana smokers who sought treatment for respiratory symptoms. Four had difficulty breathing, four had collapsed lungs, and two had lung infections. The findings are published in the journal Respirology.

CT scans identified bullae in all of the patients, with nine having severe bullous disease. Seven subjects were in-patients with acute respiratory disorders and one patient had a long history of asthma.

However, five of the patients had normal lung function and the other four had only mildly reduced lung function. Chest X-rays were normal in four patients.

It is estimated that up to 2 percent of the U.S. population are regular marijuana smokers, the researchers note. They therefore call for further study to determine how common such lung disease is among marijuana smokers and to compare pot-related lung damage to the harmful effects of tobacco.
纽约（路透健康）--通过对10个人的小型研究发现，大麻吸食者可能比吸烟者早数十年出现肺部病理改变。

患者的平均年龄为41岁，并且称至少常规吸食大麻一年。所有患者的主要特征是在肺中形成口袋，即所谓的肺大泡。肺大泡是多年吸烟者发展为肺气肿后可见的典型病理特征。

澳大利亚Monash大学的Su W. Hii和他同事注意到约有15%的吸烟者在65岁时会出现肺气肿，但是人们对大麻对肺部的影响了解甚少。研究者补充到，由于典型的大麻吸食者用力吸入热烟，并且使它尽量长的停留在肺部，因此大麻可能对吸食者的肺部的影响更为严重。

为了研究，Hii和同事调查了10例因呼吸道症状而寻求治疗的大麻吸食者。4例患有呼吸困难，4例出现肺萎缩，还有两例患有肺部感染。该发现发表于《呼吸》杂志中。

CT扫描显示所有患者都存在肺大泡，其中9例患有重症肺大泡病。7位患者是患有急性呼吸紊乱的入院患者，一位有长期的哮喘史。

但是，其中五位患者肺功能正常，另外4名患者仅有轻度的肺功能降低。四位患者的胸透结果正常。

研究者指出，据估计高达2%的美国人群为常规大麻吸食者。因此，他们呼吁进行进一步的研究以确定在大麻吸食者中，出现这样肺疾病的几率是多少，并且比较分别烟草和大麻对肺部的损伤作用。